Is there an idiom available, that is exactly opposite to "Cake walk" or "Child's play"? I am looking for something exactly synonymous with "Very difficult" or "strenuous".

Example Sentence:

This task is really _______(difficult).

  • 11
    Cake walk and Child's play don't grammatically fit into your example sentence. So anything that's an exact opposite of the same tense will also not fit grammatically into the example sentence. The way you've worded it should really just be "difficult", or "hard"
    – Cruncher
    Commented Feb 17, 2017 at 5:27
  • 3
    -1 for the reason Cruncher mentioned. It's impossible to correctly answer this question. Cake Walk and Child's Play are nouns. Your example sentence is calling for an adjective.
    – DCShannon
    Commented Feb 17, 2017 at 17:26
  • 8
    @Cruncher “This task is really child’s play” is perfectly fine, though of course cake walk is a count noun, so it would require an article. Commented Feb 17, 2017 at 19:18
  • 6
    PLEASE STOP posting comments that do not seek to clarify something about his question from the asker. Further such comments, specifically including one-line answers misposted, will be summarily deleted. Please use the provided chatroom for extended discussion.
    – tchrist
    Commented Feb 19, 2017 at 22:12
  • 6
    Why do you think adulting fits your example sentence?
    – NVZ
    Commented Feb 20, 2017 at 2:51

29 Answers 29


You could say, "It was no small feat," and mean that it was actually a very great or difficult feat. [Wiktionary] This understated way of emphasizing something is called litotes.

A herculean task is one that is all but impossible. Merriam-Webster explains,

The hero Hercules, son of the god Zeus by a human mother, was famous for his superhuman strength. To pacify the wrath of the god Apollo, he was forced to perform twelve enormously difficult tasks, or "labors". These ranged from descending into the underworld to bring back the terrifying dog that guarded its entrance to destroying the many-headed monster called the Hydra. Any job or task that's extremely difficult or calls for enormous strength is therefore called herculean.

  • 21
    Also, no mean feat. Commented Feb 15, 2017 at 14:42
  • 1
    "Herculean" was one of the first phrases I thought of in response to the question. A good short reference is here: etymonline.com/index.php?term=herculean I also considered "trial by fire," but that seems to have a particular connotation of a painful task intended to determine guilt or innocence. Apparently originally called "trial by ordeal" and was likely a sham and not really concerned with a just result. en.wikipedia.org/wiki/Trial_by_ordeal
    – jrdevdba
    Commented Feb 16, 2017 at 21:21
  • I would have used "no small feat" too, however the Cambridge Online Dictionary mentions no mean feat instead. Commented Feb 17, 2017 at 13:58
  • 8
    If this answer reaches 100 upvotes, you should probably give at least half of the resulting gold badge to Brad Thomas.
    – Sven Yargs
    Commented Feb 19, 2017 at 22:35

You could describe such a problem using the idiomatic phrase:

A hard/tough/difficult nut to crack

Cambridge Online Dictionary defines the idiom as follows:

A problem that is very difficult to solve or a person who is very difficult to understand.

Collins Online provides two different definitions:

  1. a person not easily persuaded or won over
  2. a thing not easily understood

The Free Dictionary provides the following definition and example:

A difficult problem to solve
Example: A company whose product has sold well in the States may find the European market a tougher nut to crack.

  • 4
    The ngram viewer of this is interesting! I would at least add "tough" to your bold text, instead of hiding it in the example sentence.
    – user812786
    Commented Feb 16, 2017 at 21:14
  • 2
    I wish OP had accepted this answer instead.
    – Spencer
    Commented Feb 20, 2017 at 4:34

May not be an exact opposite but you may be able to call it an uphill battle/fight/struggle.


an uphill battle/fight/struggle (also an uphill job/task)

if something you are trying to do is an uphill struggle, it is very difficult, often because other people are causing problems for you

We're trying to expand our business, but it's an uphill battle.

Cambridge Idioms Dictionary, 2nd ed. Copyright © Cambridge University Press 2006. Reproduced with permission.


A more creative alternative if you like its tone would be this idiom:

One does not simply [...your action here...] .

...coming from the well known "One does not simply walk into Mordor.". Original meme for reference:

Obviously, "walking into Mordor is not child's play" :)

  • @jpmc26 I read this again, after about a year, and yeah, it kind of makes sense. Commented Mar 6, 2018 at 22:17

A common phrase I have heard is "like herding cats," which is relatable to anyone who has ever owned a cat and tried to get them to do anything.

The first time I became aware of it was during Super Bowl 34 when it was used in a commercial for EDS, although it supposedly existed as management speak prior to that

  • 6
    We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
    – Hank
    Commented Feb 15, 2017 at 15:14
  • 6
    "Herding cats" is more about getting a group of people to do something rather than just something being generally difficult to do.
    – Kevin
    Commented Feb 17, 2017 at 0:04
  • Herding smoke is one step up on the difficulty scale from cat herding.
    – Scooter
    Commented Feb 20, 2017 at 3:45

Like pulling teeth: If you say that making someone do something was like pulling teeth, you mean it was very difficult and they did not want to do it.

Example: Getting her to tell me about her childhood was like pulling teeth. --[Cambridge Dictionary],

Other example sentences from Oxford Living Dictionaries:

  • Journalists are writing over and over again that this is the most secretive military campaign in history, and that getting information from you and your colleagues is like pulling teeth.

  • We did the show in Toronto and it was like pulling teeth to get people to participate.

While often used in reference to information extraction, it is far from limited to only that context.

  • 5
    "Pulling teeth" implies more reluctance than raw difficulty.
    – user89175
    Commented Feb 19, 2017 at 21:40
  • I disagree, one is reluctant to have one's own teeth pulled, but to pull teeth (which is what this comes from), there is no implied reluctance there. It was indeed historically a difficult process, they don't just fall out, even worse if they shatter, etc...
    – ttbek
    Commented Feb 20, 2017 at 14:30

Rocket science is an informal term meaning very difficult, where the difficulty is in skill rather than stamina. It is usually used in the negative, "this isn't rocket science", but doesn't have to be as in the following examples:

  • "Where we’re at with our telephone service, in some ways this is rocket science; nobody has done this stuff before" (Cable TV company Technical Director quoted in industry news article)
  • "Design Is Rocket Science" (Title of blog post)

(There is also a similar term brain surgery.)

  • 5
    There's also the slightly malaprop combination of the two expressions, rocket surgery Commented Feb 17, 2017 at 19:23
  • 4
    No, it does't have to be used in the negative, but de facto that is how it is used. A person who discusses a relatively easy task will say: ‘This isn't rocket science; if something's wrong, make it right.. If the project was difficult and complicated will they: "That is rocket science"? Naa... It simply doesn't fit in the OP's sample sentence.
    – Mari-Lou A
    Commented Feb 19, 2017 at 9:11

A tough row to hoe (alternatively, long row to hoe, historically hard row to hoe, recently misstated as tough road to hold):

The Free Dictionary:

    Fig. a difficult task to carry out; a heavy set of burdens.   It’s a tough row to hoe, but hoe it you will.  This is not an easy task.  This is a hard row to hoe.


    A difficult course, hard work to accomplish, as in  He knew he’d have a tough row to hoe by running against this popular incumbent.

Cambridge English Dictionary:

    a difficult situation to deal with:  Teachers have a tough row to hoe in today’s schools.


    Alternative form of long row to hoe

      long row to hoe

        A difficult, arduous task or set of tasks; a lengthy, demanding project.

Another option is heavy lifting:

The Free Dictionary:

    Fig. Serious or difficult work:  credited her for doing all the heavy lifting on the project.


    hard work:  A team of researchers did the heavy lifting for the author.


    The most demanding part of an endeavour; work requiring the most effort, resources, or consideration.

Macmillan Dictionary:

    difficult work that needs a lot of effort   With only three weeks until his contract ends, you won’t find him doing any of the heavy lifting.

There is the idiomatic expression sticky wicket:

  • a difficult or delicate problem or situation.

    • It's a bit of a sticky wicket.
    • She was on a sticky wicket when she saw her friend steal the fund-raiser money.



For a specific opposite to cake walk, or an absurdly easy task that can be accomplished with no difficulty, you could try gauntlet. This was originally a form of corporal punishment where one had to walk steadily through a line of people all hitting you with blunt instruments.

run the gauntlet
1. Lit. to race, as a punishment, between parallel lines of men who thrash one as one runs. The knight was forced to doff his clothes and run the gauntlet.
2. Run the gauntlet of something Fig. to endure a series of problems, threats, or criticism. After the play, the director found himself running the gauntlet of questions and doubts about his ability.


Sometimes a task is referred to as 'Sisyphean', after the Greek myth about Sisyphus being condemned eternally to repeatedly roll a heavy stone up a hill, only to have it roll down again.

That term certainly suggests a strenuous task that's effectively impossible, although perhaps most specifically in the sense of it being never-ending rather than simply requiring a huge amount of effort to complete.

  • 6
    It also, though, implies a uselessness to the task, which may or may not be what the OP was looking for. (Just clarification for someone looking for a word; still +1)
    – Unrelated
    Commented Feb 15, 2017 at 18:17
  • 3
    This crossed my mind, but Sisyphian is more about the perpetuity of a difficult task, rather than its actual difficulty.
    – Kevin
    Commented Feb 17, 2017 at 0:05
  • 3
    I always associate Sisyphean with something that is impossible to complete rather than simply difficult/hard to complete.
    – mccainz
    Commented Feb 17, 2017 at 13:55

There are the expressions nailing jelly to a wall and wrestling with an octopus.

It was like trying to nail jelly to a wall.

Solving the problem was like wrestling with an octopus.

  • 1
    Never heard the octopus one, but definitely heard the jelly one.
    – AndyT
    Commented Feb 15, 2017 at 11:19
  • I always thought "wrestling with an octopus" was for the case whereby you're trying to do multiple things at the same time.
    – SGR
    Commented Feb 15, 2017 at 14:17
  • 2
    Not really because there's only one octopus, it's for when you're really struggling with a particularly complicated task. The idiom for trying to do several things at once is 'spinning plates' as in the circus or variety act.
    – Chris M
    Commented Feb 15, 2017 at 14:27
  • 1
    Related: "pushing a rope"
    – Patrick M
    Commented Feb 15, 2017 at 21:45
  • 3
    Also "herding cats". These are good (and funny), but some of them have narrower implications than merely "difficult" in a generic sense. For example, "nailing jelly (or jello) to the wall" frequently implies struggling with ever-changing requirements, etc.
    – BradC
    Commented Feb 15, 2017 at 21:57

I typically use "Nightmare" in this context.

One of the definitions according to oxford:

A person or situation that is very difficult to deal with: ‘buying wine can be a nightmare if you don't know enough about it’


One word answer: a pickle

Example: That's gonna be a real pickle

obviously, this is colloqual so don't use it in a business enviroment.

From Urban Dictionary:

TOP DEFINITION pickle a tricky situation; a conundrum i love him and he loves her and she's my mom.... it's a pickle.

  • 1
    The colloquialism isn't an issue as it's a proposed antonym for "cake walk"
    – Cruncher
    Commented Feb 15, 2017 at 22:41
  • Yeah, not really.
    – Kevin
    Commented Feb 17, 2017 at 0:06
  • I agree, 'pickle' is typically used for a moral or ethical dilemma rather than a task.
    – neontapir
    Commented Aug 31, 2017 at 21:39

In moments like this we can turn to the masterpiece that is "How Do You Solve A Problem Like Maria?"

  • "catch a cloud and pin it down"
  • "keep a wave upon the sand"
  • "hold a moonbeam in your hand"


  • "pester any pest" (doesn't seem too difficult)
  • "drive a hornet from its nest" (nor does this one really)
  • "throw a whirling dervish out of whirl"
  • 3
    Legit if you said any of these on the phone at work I'd think "okayyyy... weird. hope that's not their company culture." and reconsider if we should be dealing.
    – MickLH
    Commented Feb 16, 2017 at 8:52
  • I don't think I would use a phrase that implies harassment of a Sufi Muslim during his religious meditation. For comparison, replace that reference with another minority group and attempted disturbance of a stereotypical intense activity. Commented Feb 17, 2017 at 14:39
  • 2
    @SpehroPefhany Because this site is always so sensitive... (but I agree, that is poor logic to use as defense. I'll take out the personal favorite comment, but leave the example 'cause I'm just copying the source :) )
    – Unrelated
    Commented Feb 17, 2017 at 16:43

Here is an old fashioned idiom that might interest the OP. It means to attempt the impossible, or to place one difficulty on top of another.

To pile (or heap) Pelion on Ossa

Add an extra difficulty to something which is already onerous.
‘But was it worth while to heap Pelion on Ossa, to shake the whole world, to create such a cataclysm of colour, merely to raise a smile?’

Oxford Living Dictionaries

A wooded mountain in Greece, near the coast of SE Thessaly, rising to 1,548 m (5,079 ft). It was held in Greek mythology to be the home of the centaurs, and the giants were said to have piled Mounts Olympus and Ossa on its summit in their attempt to reach heaven and destroy the gods.

Knowing the idiom itself will set you apart from the masses.

  1. This task is like piling Pelion on Ossa, as my professor of Classics was fond of saying.

If the OP is looking for the opposite of cakewalk (usually spelled as one word), then in British English there's the idiom wade through treacle

  1. This task is like wading through thick treacle.

The British term treacle can be substituted with the AmEng molasses, without changing its meaning.

  • 1
    Strangely ironic considering the down-vote pile-on on the accepted answer ;) Commented Feb 17, 2017 at 4:53
  • 3
    @BradThomas Your answer has been heavily downvoted NOT by the core EL&U members, but by the hoards from the Hot Question Network circuit. It is most unfortunate that there is no fixed limit for DV, for such a high number of DV I would expect to see a semi-illiterate answer, which your isn't. Your solution is not the best, or the most appropriate, but it does offer a novel twist.
    – Mari-Lou A
    Commented Feb 17, 2017 at 9:25
  • 5
    @Mari-LouA most HNQ visitors can't downvote. As you need a rep of 125 and totally new people will only have 101. Commented Feb 18, 2017 at 18:42
  • 1
    @MartinSmith I can't believe all 52 DVs (so far) are from EL&U regulars. I've never seen such heavy downvoting on EL&U. It's an exaggeration, and 8k views? That's definitely from HNQ, probably fuelled by Brad Thomas's answer.
    – Mari-Lou A
    Commented Feb 18, 2017 at 19:19
  • @Mari-LouA I'm a semi-regular (visitor, not poster) but I still can't downvote with 103 rep. HNQ is responsible for the hoard of visitors on the question. But certainly the ones who downvoted have some sort of familiarity with the site - to have gained 125 rep. Commented Feb 19, 2017 at 23:59

You could say "It was a grind."

Though it's meaning may be closer to "exerting a lot of effort for very slow progress".

So it may not be exactly what you are looking for.


"Like walking a tight-rope" implies that the task is difficult, requires great skill, constant attention, and a willingness to continually make small adjustments. If the tight-rope is high enough, it is also very dangerous.

  • 1
    I like this one. I thought death march would be a good vs. cake walk. But, this is better as you can do both. I dunno why you'd want a cake walk on a tightrope, but there's some nice advantages there.
    – Tatarize
    Commented Feb 19, 2017 at 4:10
  • 1
    @Tatarize -- You should suggest "death march" as an answer. There is both the literal version (such as the Bataan Death March) and the figurative version used by programmers and engineers.
    – Jasper
    Commented Feb 19, 2017 at 6:25

It might be a bit extreme but a Suicide Run implies pretty much the maximum level of difficulty. Of course in movies, often enough when the Heroes go on a Suicide Mission they still end up escaping alive by the end.



Dictionary.com says of non-trivial, as used in technology:

Requiring real thought or significant computing power. Often used as an understated way of saying that a problem is quite difficult or impractical, or even entirely unsolvable ("Proving P=NP is nontrivial"). The preferred emphatic form is "decidedly nontrivial".

This can be extended to non-technical situations for example:

Persuading my children to eat their vegetables is a non-trivial job.

It fits cleanly into the OP's sentence:

This task is really non-trivial.


Another idiomatic expression which may work is "near to impossible" (also, next to impossible).

This task is really near/next to impossible.


be near to impossible

To be of such difficulty as to be or seem almost impossible.

The promises of the candidate during her presidential campaign are near to impossible to achieve, but they have garnered a huge following of dedicated supporters.

Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

next to


It is supposed to be next to impossible to escape from a high-tech, maximum security prison.

Cambridge Dictionary of American Idioms Copyright © Cambridge University Press 2003. Reproduced with permission.


As a Naval Aviator I often use the term "Varsity" to describe a very challenging situation as do many of my fellow Aviators.

After a very difficult approach and landing in very challenging conditions it would be a common response to say: "It was varsity out there tonight", in response to a question about the difficulty caused by the evening's weather.

  • Scooter: Just one citation from a blog or something would probably do the trick.
    – J.R.
    Commented Feb 20, 2017 at 19:27
  • We have another term we use (tongue in cheek) for a situation like this which is to say: My "too hard" light just came on"...
    – Scooter
    Commented Feb 20, 2017 at 19:30

Please excuse the vulgar term but in my opinion this is the exact opposite of a cake-walk

A shit fight

The Urban Dictionary defdines it as

A great, messy struggle, such as a freeway at rush hour or registration at a large university.


It is fairly commonly used in Australia to mean something that is such a hassle it is not worth doing and should be avoided if at all possible.


How about daunting: tending to overwhelm or intimidate; ex: a daunting task



I like "a bear". "The engine on the Dodge Challenger is a bear to drop and rebuild."

I don't know if it's shortening of "a bear to wrestle", a mincing of "a bitch", both, or neither.


I suppose the exact opposite of a "cake walk" would be a "tight rope." The closest albeit simplest opposite of "child's play" would be "hard work."


You could say it was like trying to unscramble an egg. For example: Solving that problem was like trying to unscramble an egg.

  • 2
    That would imply an impossible task as opposed to a difficult task
    – Thomo
    Commented Feb 16, 2017 at 4:17

The opposite of a "cake walk" is quite clearly the "cluster fuck" or "shit storm" or something on those lines

There's probably less offensive ways to express it, but I don't thing anything describes difficulty, frustration, and struggle quite so well as profanity.

  • 4
    Not acceptable. An unnecessary term to use here.
    – user163849
    Commented Feb 19, 2017 at 3:46
  • 4
    @YvetteColomb I.M.O., the fact that this contains so–called obscene words is less important than the fact that the slang are more applicable to “disaster” or “mayhem” than to “strenuous”. The speaker for whom this writ is purposed may be a foul–mouthed brawler. Commented Feb 20, 2017 at 7:07
  • 1
    I agree with @can-ned_food that the language is not important. People have differing opinions on what is considered "obscene" and it's not being used in a vulgar sense like it being directed at someone. They are legitimate phrases, just not for this situation, as can-ned_food mentioned.
    – Hank
    Commented Feb 20, 2017 at 14:09
  • This is the best answer for the Boston/New York part of the US; these words are no longer obscene there, and they describe exactly the OP is asking for. Commented Feb 20, 2017 at 14:25
  • 3
    @YvetteColomb Stack Exchange recognizes a use-mention distinction. The answer above does not use profanity: it mentions it. Stack Exchange management only discourages the use of profanity. Questions and answers that mention profanity are not discouraged, assuming the mention is useful/relevant.
    – MetaEd
    Commented Feb 20, 2017 at 15:18

A "hard slog".

There are plenty of online references.

  • 3
    Yes, you're right, there are, but merely saying “There are plenty of online references” without quoting them and linking to them here is not up to site standards. Could you please do that for us, perhaps adding more of your own words, too?
    – tchrist
    Commented Feb 19, 2017 at 22:26
  • no, actually, i'm quite satisfied with the answer as it is. Commented Mar 25, 2017 at 3:40

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