I understand the meaning of the word sufficient like defined in Merriam-Webster:

sufficient = enough to meet the needs of a situation or a proposed end

So mathematically said:

not less than the needed minimum

Is there an "upside-down counterpart"?

not more than the needed maximum

It should be of the same style as sufficient or enough, expressing the same concept (being within limits and not being under the maximum).

Let's have an example of a chemical reaction. In order the reaction can start, you need at least 5% concentration of a given substance. So if the concentration is 6%, we say that the concentration is sufficient. (Also suggesting that no more concentration increasing is needed.)

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However, what if the requirement is that in order the reaction can start, the concentration of the given substance should be at most 95%. So if we have 94%, the concentration is ...? Sufficient here sounds funny...

Analogically, it should also bear the notion of no more concentration decreasing is needed.

enter image description here

I am searching for a single word in the same common style as enough of sufficient, not for a mathematical expression.

N.B.: I do not mean the same as in the related question Can "sufficient" be used in a negative sense?

  • 1
    why can't you just use the phrase "not too much"? (or in this particular case, "not too high.") Or alternatively, you could perhaps say "sufficiently low" or "low enough." I don't see why you need a single word.
    – herisson
    Sep 11, 2015 at 9:57
  • 1
    "not more than the needed maximum" is incoherent. A needed maximum means both no more (the maximum) and no less (needed).
    – Mitch
    Sep 11, 2015 at 12:31
  • 2
    @HonzaZidek your logic is faulty - Sufficient comes from 'suffice' - in other words "does the value suffice in meeting your needs?" - Your needs are that the value must fall within an upper and lower boundary. A value within those values does suffice as it meets your conditions- it is therefore 'sufficient'.
    – Marv Mills
    Sep 11, 2015 at 13:03
  • 2
    It is sufficiently concentrated, so I do not need to change the concentration.
    – Marv Mills
    Sep 11, 2015 at 13:37
  • 2
    "Sufficiently low" is exactly right! Sep 11, 2015 at 18:36

16 Answers 16


I think “sufficient” covers the whole range between insufficiently low (too low) and insufficiently high (too high), but I do agree that “sufficient” (and especially “enough”) can imply that the lower end of that range has been (just barely?) reached.

Just as, imo, “sufficient” covers the whole acceptable/sufficient range (with a bias towards the low end), so does “tolerable” cover the whole acceptable/tolerable range, but perhaps with the bias towards the high end that you are seeking.

“Tolerable”: adjective/ bearable, endurable, supportable, acceptable. (Oxford Dictionnaires)

Step 1: Insufficiently low/intolerably low (too low) = insufficient/intolerable/unacceptable);

Step 2: Sufficiently high/tolerably low (high enough/not too low) = sufficient/tolerable/acceptable;

Step 3: Tolerably high/sufficiently low (not too high/low enough) = tolerable/sufficient/acceptable;

Step 4: Intolerably high/insufficiently high (too high) = intolerable/insufficient/unacceptable.

The above steps are trying to show that “insufficient, sufficient, tolerable, and intolerable” can be used at both ends of the range of acceptability, but please note that the bolded words in each step are, in my opinion, ‘best suited for’/most often associated with that step.

Both “insufficiently” and “intolerably” use “low” in Step 1 and “high” in Step 4 to convey the meaning of those two Steps, which could mean that the bias towards either the low end (sufficient) or the high end (tolerable) that I perceive in these two words disappears when discussing unacceptable levels below and above the acceptable range.

Within the range of acceptability, however, “high” and “low” must be flipped to make sense of “tolerable” and “sufficient” as they are used in Steps 2 and 3, which, imo, supports the bias that I perceive and perhaps supports “tolerable” as the best one-word answer to your question.

  • It's true that SamuelVimes came with tolerable before you, but as I do not agree with the rest of his answer (namely the claimed "symmetry" of sufficient towards both ends), I tend to accept your answer tolerable as sufficient :) (unless someone comes with something even better) Sep 11, 2015 at 14:31
  • Thanks, but my answer came long after @Samuel 's (I missed his mention of 'tolerable' until after posting mine, but instead of deleting mine I chose to leave it and upvote his) and I also agree with Samuel that 'sufficient' covers both ends (with a bias towards the lower end), so please don't accept mine over his for that reason alone, or for any reason, for that matter. Thanks.
    – Papa Poule
    Sep 11, 2015 at 14:47

Quite simply "not in excess".

Since excess means:

An amount of something that is more than necessary, permitted, or desirable:

and in excess means:

Exceeding the proper amount or degree

(from ODO)

So if something is in excess then it is more than sufficient.

  • An amount which is "barely sufficient" can also be described as "not in excess". This isn't specific enough for the asker's needs.
    – talrnu
    Sep 11, 2015 at 19:37
  • @taimu While this is literally true, my experience is that it is not usually used in that manner. If I am given only one bound, I attempt to get rather close to that bound. The same way, if I were told 5% is enough, I would not go for 95%.
    – trlkly
    Sep 12, 2015 at 0:25

This can also be referred to as an appropriate. It is a general word, not necessarily meaning that levels are in the desired range, but given the context, I think it is clear. suitable might serve well as well.




Suitable for a particular person, condition, occasion, or place; fitting.

Source: TheFreeDictionary.com

  • 2
    While this doesn't precisely specify the bounds the question asked for, I think it is likely the best we can get with a single word answer. Since the asker emphasized the single word requirement, +1 for that. Sep 12, 2015 at 15:27

By the same definition you have given:

sufficient = enough to meet the needs of a situation or a proposed end

But in my opinion that does not translate to:

not less than the needed minimum

But rather to:

not less than the needed minimum AND no more than the allowed maximum

As in your case, exceeding such limit doesn't allow you to meet the needs or requirements of your situation. So I would still say that 94% concentration is sufficient. However, if you prefer, you could say that the concentration is within parameters o within limits. Also, perhaps you can say that it is an acceptable, tolerable or adequate concentration, to imply that it is within limits.

  • Well, I was asking for a single word :) Sep 11, 2015 at 9:39
  • 1
    The sentence "The 94% concentration is sufficient to start the reaction" is very misleading in the case where the 96% concentration is too much and the reaction will not start. Sep 11, 2015 at 9:41
  • 2
    Agreed - if the word were negated, and I was told that the 96% concentration was "insufficient", I would increase the concentration. Sep 11, 2015 at 9:56
  • @Matt & Honza: But that is because your initial assumption is incorrect. Sufficient does not actually mean "enought" but rather, "satisfactory" or "adequate". To put it differently: if something is sufficient it is because it adquately fullfills the requirements. Another thing is that, as the requierements we normally find in our lives have a lower bound rather than an upper one, we tend to associate a minimum condition with a sufficient one. Sep 11, 2015 at 10:28
  • @SamuelVimes: "sufficient," "satisfactory," "adequate" all seem to be synonyms of "enough." I get what you're saying, but I agree with Honza Zidek that it doesn't sound right to use "sufficient" to mean "not too much" in this kind of context.
    – herisson
    Sep 11, 2015 at 10:45

You could say the 94% concentration is effective. However, this doesn't really address whether it's possible to have too much, or too little, or both. It won't lead to any incorrect interpretations, though.

  • 1
    Although you really could say that, it doesn't answer my question and maybe should rather be a comment (however valuable and relevant) :) Sep 11, 2015 at 9:56

The closest word I can think of off the top of my head is requisite, which in my mind implies an exactness of quantity (as opposed to enough/sufficient or more than enough/plentiful). That said, the literal definition of requisite in the dictionary includes an allusion to the word necessary, thereby leaning towards "above the minimum" and not necessarily answering your question.


Unless I miss my guess, you're looking for a word from the 'common' language (using as models 'sufficient' and 'enough') that means 'at least X but no more than Y'.

That word is 'competent':




  1. Being what is needed without being in excess

(competent. (n.d.) The American Heritage Roget’s Thesaurus. (2014). Retrieved September 12 2015 from http://www.thefreedictionary.com/competent).

So, paraphrasing the the example you give,

concentrations from 5% to 95% are competent to produce the reaction


a concentration of 6% is competent to produce the reaction

as well as

a concentration of 94% is competent to produce the reaction

In each case the intended meaning of 'enough but no more than enough' is expressed by 'competent'.

  • So a solution of 94% is competent? That wording doesn't seem to work for me. But, "competent" may work in other contexts.
    – herisson
    Sep 13, 2015 at 7:38
  • @sumelic, why doesn't it work for you? I edited hard science manuscripts for years, and that use of 'competent' is acceptable (would be understood), although the more usual approach would be to spell out the range.
    – JEL
    Sep 13, 2015 at 7:42
  • Sorry, I didn't read your answer all the way before commenting. It looks like this is a fine word to use. It sounds odd to me. But this is probably just because I have never written or edited a science manuscript.
    – herisson
    Sep 13, 2015 at 7:49

Since you mention mathematics, it is worth mentioning that sufficient usually is contrasted with necessary. A simple example: Let A be the statement

The function f is continuous,

and B the statement

The function f is differentiable.

Then B implies A, i e B is the stronger property of f. This can be expressed as:

B is sufficient for A.

Another way to say this is:

A is necessary for B.

  • 1
    In my example the sentence "The 94% concentration is necessary to start the reaction" would have quite a different meaning be default, I'd say. Sep 11, 2015 at 9:43

I think the word you are looking for is maximal. As in the maximal concentration of the substance for the reaction is 94%.

of or constituting a maximum; as great or as large as possible.

  • But here, the maximal concentration of the substance for the reaction is actually 95%.
    – herisson
    Sep 11, 2015 at 10:43
  • Also, even if you disagree or aren't sure about that, since the definition is only "not more than the maximum," whatever term used has to also apply to 93%, 92%, 91% and so on, which are clearly not the maximum concentration of the substance for the reaction. "Maximum" specifies a single point; the OP is looking for a word that refers to a range of values.
    – herisson
    Sep 11, 2015 at 18:03
  • Agree - I think it would be clearer if the question used a number not so close to the limit in order to make this clearer. Sep 14, 2015 at 8:17

How about "in range". It states not to exceed the maximum (nor the minimum, if any). It doesn't imply being near the maximum though, which you seem to be searching for.

"The 94% concentration is in (the) range to start the reaction"

  • 1
    I completely miss the implicit message which I feel sufficient or enough bears towards the low end, but here towards the high end, i.e. "no need to (further) decrease the amount". Sep 11, 2015 at 16:11

One word that comes up somewhat regularly in scientific contexts is parsimonious:

1: exhibiting or marked by parsimony; especially : frugal to the point of stinginess

2: sparing, restrained


a : the quality of being careful with money or resources : thrift

b : the quality or state of being stingy

2: economy in the use of means to an end; especially : economy of explanation in conformity with Occam's razor

(from Merriam-Webster)

A parsimonious theory is one which doesn't involve any extraneous features. A parsimonious evolutionary tree is one which minimizes the number of evolutionary "events" (mutations) which occurred.

So a "parsimonious concentration of reactant" would be interpreted as being the bare minimum needed to show the desired effect, with none extra or "wasted".

(All that said, I will admit I've never heard "parsimonious" used to describe compound concentrations, although I can't ever recall a situation where such a single word phrasing would have been needed.)

  • So parsimonious means enough, sufficient... Sep 11, 2015 at 17:43
  • Yes, parsimonious implies having enough, but without having much more than the minimum required.
    – R.M.
    Sep 11, 2015 at 23:19
  • I don't think parsimonious really implies sufficient to any problematic degree, at least in general language use. It's a common generalisation of thrifty (virtue) and avaricious (vice). A connotation of sufficient is unavoidable just like it's unavoidable that sufficient connotes parsimonious: "The water in your bathtub is sufficient. (In fact, I nearly drowned when opening the bathroom door.)" - "The water in your bathtub is parsimonious. (In fact, I removed the plug hours ago. I just didn't get around to drying it up.)" Both are misleading in the same way.
    – user86291
    Sep 12, 2015 at 6:27
  • The problem with parsimonious is not so much in the degrees it describes as in the kind of scales it is usually applied to. It still has a very strong connotation of being about money. But as a metaphor it seems to be a very good solution to the problem.
    – user86291
    Sep 12, 2015 at 6:29

i strongly believe that there is something very, very, very wrong with the "needed maximum" wording in the first place.

Different story if you said: the maximum allowed, which means that if you pour more, things will go wrong.

If you persist in such ill wordings, i believe you'll end up entangled in the quest for a language chimera that will haunt you for life.

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    – choster
    Sep 11, 2015 at 22:21
  • This is a valid point but it should be a comment (yes, I know you can't).
    – Mazura
    Sep 12, 2015 at 1:52

When discussing the amount of food (or alcohol) that I’ve just consumed/am consuming, I often talk in terms of the progression from 1) “too little/not enough,” to 2) “enough,” to 3) “full,” and finally to 4) “too much,” where “full” might fit somewhere in your nice graphs.

However, although “full” (or the fancier “saturated" in non-chemical contexts) does convey that no more increasing is possible, permitted, or needed; it admittedly doesn’t bear the notion you're after that “no more decreasing is needed.” (The Free Dictionary)

  • "saturated" seems similar, but unfortunately in a chemical context like the one in the original post it has a specific and distinct meaning.
    – herisson
    Sep 11, 2015 at 18:22

I would say you want a moderate amount:

Kept or keeping within reasonable or proper limits; not extreme, excessive, or intense

(From Dictionary.com)

You could also say that you want just enough of something (though this is a phrase rather than a single word).


Presumably, the "needed maximum" you refer to is so needed because it describes an arbitrary limit less than the "possible maximum". For example, when you're filling your car's gas tank, the "needed maximum" gas to dispense is equal to the tank's capacity, while the "possible maximum" gas to dispense is limited by how much fuel the station has in storage. If you fill your gas tank to the "needed maximum", you can say you've filled it to capacity, and if you continue to dispense gas beyond that point, you can say you've overfilled the tank.

Therefore, a term that satisfies your requirements is capacity. You could also use limit (e.g. "filled to its limits"), extent (e.g. "prosecuted to the extent of the law"), and so on in the same manner.


In object relations theory, one writes of and holds in high esteem the "good enough" mother, or the "ordinary devoted mother," meaning a mother who is adequate to the task of mothering, not perfect or, pejoratively, perfectionistic. Competent and adequate work well as synonyms; the antonym would be inadequate.

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