I'm looking for a single word synonym for "A person not to mess with" without explicitly evoking a specific reason, as in "fearsome" for example.

Example in a sentence:

Kidd was an unfuckwithable pirate for my lack of a better placeholder.

  • 99
    I dunno. I like your word. Commented Jan 9, 2019 at 18:48
  • 5
    How about BAMF?
    – MooseBoys
    Commented Jan 10, 2019 at 3:13
  • 8
    "chucknorrisy"? Commented Jan 10, 2019 at 8:12
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    BigBadJohn ? This goes back a ways. Commented Jan 10, 2019 at 11:42
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    It's a great question, and your created word is perfect. Bravo. Note that the somewhat archaic word "redoubtable" does mean precisely unfuckwithable, but it sounds old-fashioned. Fearsome is OK but doesn't sound as cool as unfuckwithable. Note that the common phrasing "John was a person not to be messed with" is a common approach.
    – Fattie
    Commented Jan 11, 2019 at 13:12

9 Answers 9


I'd go with Formidable. According to Cambridge Online:

Formidable: adjective: causing you to have fear or respect for something or someone because that thing or person is large, powerful, or difficult:

Comparison with other answers so far:

  • Redoubtable: Means pretty much the same thing, but is more archaic.
  • No-nonsense: Means the person doesn't mess around. This is not the same as not to be messed with
  • Badass: Is informal, and directly suggests the person is violent. Formidable doesn't directly suggest violence. If you are a formidable chess player, then your opponents should have fear or respect of your skills; but you are not a badass because there is nothing violent about this. Another difference is "That guy is a badass!" usually means something like "That guy is cool!" and is usually positive, while "That guy is formidable" is not obviously positive or negative.
  • Awesome: The word has an archaic meaning of 'inspiring awe' which is similar to respect. However the modern meaning of the word is just slang for 'good'. In fact due to language degradation it's a pretty weak word for good.
  • Terrific: The archaic meaning is 'inspiring terror' which is like respect but different. The modern meaning is again just 'good' but even then it can sound a bit pip pip cheerio old chum British colonialism.

The formidable trees in Pokemon are formidable because they cannot be cut down. They are stronger than the other cuttable trees. If the stronger trees appeared as obstacles there would be no way through and the came would be impossible to finish.

  • 14
    I believe this is the closest to what I wanted, but I can't help but have a positive connotation for "formidable" because of French!
    – Outman
    Commented Jan 9, 2019 at 15:30
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    Awesome (or terrific) would be quite good alternatives for causing you to have fear or respect for something or someone, especially the former (which also fits your good at whatever it is… definition well). Commented Jan 9, 2019 at 17:12
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    I agree with this answer if the person "not to be messed with" is generally assumed to only use above-board tactics. Formidable opponents generally don't cheat to win, whereas a person "not to be messed with" generally keeps all options on the table... Commented Jan 9, 2019 at 18:25
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    You can also find a few more common, similar words that haven't been mentioned yet in a thesaurus entry Commented Jan 10, 2019 at 7:41
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    A Robinet is an example of what are sometimes called faux-amis. The word sounds like the English Robin but is actually the French word for Faucet.
    – Daron
    Commented Jan 10, 2019 at 14:14

I sense someone labeled a badass should be avoided!

  • Kidd was a badass pirate for my lack of a better placeholder.

badass Collins Dictionary

If you describe someone as a badass, you mean that they are very tough or violent.

  • What I'm exactly looking for is to describe someone solely based on the factor of unfuckwithability alone without explaining why. It's not only the tough or the badass, you could also say that "Kidd was a Machiavellian" or "malignant" for example.
    – Outman
    Commented Jan 9, 2019 at 15:23
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    @Outman even after 4 answers and your comment, it is more unclear what your are seeking, especially a single word for such.
    – lbf
    Commented Jan 9, 2019 at 15:27
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    This fits the question better because it's a noun not an adjective. Commented Jan 10, 2019 at 10:03
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    A badass is generally seen as a compliment - you wouldn't use it for someone you didn't like. Saying they weren't to be messed with covers all areas. Commented Jan 14, 2019 at 12:03

Another possiblity is daunting,

tending to overwhelm or intimidate

which would seem a pretty good description of a well-known bad-ass.

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    I'm not sure I've ever seen "daunting" describe a person. Is that usage common?
    – piojo
    Commented Jan 10, 2019 at 7:30
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    @piojo - Nope. I have seen it but not often. Seems like a good use, though. Commented Jan 10, 2019 at 12:49
  • It seemed like a daunting task to overcome his opponent. Daunting to me also conveys that something is do-able, but discouraging.
    – Jim Wolff
    Commented Jan 11, 2019 at 11:03
  • @piojo Common enough. “Joe was widely regarded as a daunting opponent, due to his history of effortlessly decapitating dozens of highly skilled adversaries in personal combat.” Commented Jan 11, 2019 at 18:54
  • Maybe it's regional, or it depends on the genre of books you read. My first thought was that this is definitely incorrect usage, but I'm willing to believe it's a matter of style. (I read it as the opposite of personification: referring to a person as a situation, much akin to nouning a verb.)
    – piojo
    Commented Jan 12, 2019 at 5:21


very strong, especially in character; producing respect and a little fear in others:

Tonight he faces the most redoubtable opponent of his boxing career.


If you say Kidd was a redoubtable pirate, you say he was formidable as well as someone to be feared (not to be messed with).


The word you are looking for is a compound adjective, in an attributive use: "no-nonsense"

Kidd was a no-nonsense pirate.

Cambridge Dictionary Online:

no-nonsense; adjective [ before noun ] UK ​ /ˌnəʊˈnɒn.səns/ US ​ /ˌnoʊˈnɑːn.sens/ ​ practical and serious, and only interested in doing what is necessary or achieving what is intended, without silly ideas or methods: a no-nonsense manner/leader a no-nonsense approach to child-rearing

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    My grandma was no-nonsense... I don't think that word evokes the picture that OP is trying to draw with his pirate.
    – JeffC
    Commented Jan 11, 2019 at 20:08

invulnerable or invincible

Both are very strong words.

Blackbeard was thought to be invincible even some time after he was decapitated, as it is legend that his body searched for his head, and his head continued to laugh and talk.

  • Hi Mike, this might end up a good answer but at the moment it's just an unsubstantiated personal opinion. An answer on EL&U is expected to be authoritative, detailed, and explain why it is correct. Can I suggest you edit your answer to provide more information - e.g., add a published definition of the two words (linked to the source) and why they are "very strong"? For further guidance, see How to Answer and take the EL&U Tour :-) Commented Jan 10, 2019 at 3:24

Aposematic describes the effect the pirate has on other people by signaling danger.

From Mariam Webster Online:

Aposematic: adjective: being conspicuous and serving to warn

This particular behavior is known from the zooligical sciences and accurately describes the "not to mess with" signal. From Encyclopaedia Britannica online, emphasis added:

Aposematic mechanism, biological means by which a dangerous, or noxious, organism advertises its dangerous nature to potential predators. The predator, having recognized the dangerous organism as an unfavourable prey, thereupon desists from attacking it. Aposematic, or warning, mechanisms have evolved along with protective systems; it is advantageous for the protected organism not to risk the injury that is likely to occur in even a successfully repelled attack by a predator.

The most common aposematic mechanism is the possession of bright, contrasting colours, such as the black and yellow of many wasps and the red of ladybird beetles. Other organisms, such as the North American rattlesnakes, employ acoustic warning systems.



Example usage:

"That one, he's trouble."

Not sure if that usage is current, but it was very common when I was growing up in the 60's and 70's.

  • That's a good word! But consider you might say "That little girl is trouble" and not mean the same as "she's not to be messed with".
    – Daron
    Commented Jan 14, 2019 at 14:05
  • @Daron Yes, the usage varies with context. Commented Jan 14, 2019 at 14:29


[2]b : one that is among the largest or most powerful of its kind


Not in common usage

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