I'm looking for a word that is the opposite of "adaptable." I would like to say "unadaptable," but that's not a real word according to my dictionary. So, what's the best word out there for not-able-to-change?

Update: I'm embarrassed to admit I was accidentally searching the Mac's built-in thesaurus, not dictionary, when I checked to see if unadaptable was a word. My bad! I'll still award Jasper the answer for pointing out my obvious oversight.

Update 2:

To respond to the various calls for clarification, I'm specifically using this word in a report talking about the development of certain kinds of subdivisions, especially very homogenous single-family subdivisions in outer ring suburban areas. In my report I'm referring to a neighborhood that can change at the micro-level, ie. it can improve or deteriorate, but it cannot change what it is: ie. the infrastructure pattern is not capable of supporting a different land use, and it is not economically feasible to retrofit the infrastructure, therefore the nature of the subdivision cannot be changed, while the condition of the subdivision (if it is deteriorating) may cause people to wish that it could be changed.

So, with that in mind:

  1. Why not immutable?" Immutable is a great word, but I understand it's connotation to mean "permanent, unchanging", in the sense that something simply is not subject to change, not that it might like to change but cannot.

  2. Why not "inflexible?" Inflexible connotes being "unwilling" to change, or perhaps being able to be changed (or reshaped / bent) but only slowly and with much resistance.

So, in this situation I am looking for an adjective that describes an inability to adapt to changing market conditions by shifting from one land use to another. In this case I specifically use the word "adaptable" in many places to describe the opposite, and given the context I think "unadaptable" will be better understood than any of the other suggestions, even though I am aware of (and agree with) the comments about it's status as a rarely used and therefore imperfect choice.

Thank you all for the feedback!

  • Which dictionary says it doesn’t exist? A couple of online sources list it (vocabulary.com/dictionary/unadaptable) (thefreedictionary.com/unadaptable) Aug 22, 2012 at 20:48
  • 3
    I'd like more context. A software system might or might not be adaptable (or extensible, as it's sometimes called). So might a refrigerator (some allow the door to swing in the opposite direction, some don't), or an automobile, or the plumbing of a house ("I can't find a drainage line that you can use for your new washing maching," said the plumber), or even a person (to new ideas). What kind of objects are you hoping to describe?
    – J.R.
    Aug 22, 2012 at 23:59
  • Some of the answers below are for 'unwilling to change' as opposed to your request for 'unable to change'. I second J.R.'s request for more context. Are you talking about a person or a thing?
    – Jim
    Aug 23, 2012 at 0:38
  • 2
    Even if the word "unadaptable" did not appear in any dictionary, it would still be perfectly legitimate (as long as something like "inadaptable" wasn't already in wide use.) It is totally acceptable to construct words in this manner. Aug 23, 2012 at 2:18
  • @EvanHarper, I appreciate that take on this. Thanks!
    – Andrew
    Aug 24, 2012 at 20:44

10 Answers 10


The opposite of adaptable is unadaptable.

  • Oh my, I just realized I was using the Mac's built-in thesaurus, not dictionary, trying to check if 'unadaptable' was a word. Thanks for catching my blunder. :)
    – Andrew
    Aug 22, 2012 at 20:48


Not subject or susceptible to change, unchanging through time; unalterable; ageless

  • Exactly the word I was trying to remember.
    – neil
    Aug 23, 2012 at 12:12
  • This is the first thing I thought of because of: chattr +i myfile
    – TecBrat
    Aug 24, 2012 at 20:54

Consider inflexible, “not capable of bending or being bent” or “Not willing to change”; also strictured, of restricted or limited behavior or action.

  • 2
    OP says he's looking for "the best word", but it's not clear what criteria he has in mind. Given that he is unadaptable flatlines in NGrams (and that it's underlined in red by my browser's spell-checker), I would advise OP to give considerable weight to prevalence of usage, and go for inflexible as the "best word". Aug 22, 2012 at 21:12
  • "Strictured" is a neat word, thanks for sharing! That said, I don't think it will be familiar to my audience, and in the context I'm working in I think that "unadaptable" will be more easily understood.
    – Andrew
    Aug 24, 2012 at 20:45

Submitted for your approval:



I might go with hidebound. From NOAD:

unwilling or unable to change because of tradition or convention: you are hidebound by your petty laws.

These also work: reactionary, dyed-in-the-wool, and rigid.


Constant, fixed, carved in stone.


Being a programmer I would say immutable, although the context in which you wish to use the word would help.


I like some of the answers, but I thing rigid has the advantage of being a short word.


These are some strong metaphorical terms which I like to use for organizations or people who are extremely resistant to change:

  • Calcified
  • Fossilized

If it’s a more-technical application, static might be what you’re looking for. Stuck might also work, as in “stuck in their ways”. If you’re going for a bit of flair (or a subtle weight-based insult), inertial may also serve your needs.

Not the answer you're looking for? Browse other questions tagged or ask your own question.