Someone has just pointed out a mis-spelling on my site - demonstratable, as in "demonstratable experience of...".

I can't see it in the New Oxford American Dictionary or the Oxford Dictionary of English. A quick Google shows it in the Merriam-Webster dictionary, but it has a note attached:

This word doesn't usually appear in our free dictionary, but the definition from our premium Unabridged Dictionary is offered here

The closest matching word seems to be demonstrable (which means the same but sounds like it shouldn't!).

My question is, is demonstratable a recognised dictionary word or just one that is generally accepted? Where do these edge-cases fit in? For example, when writing copy for a website or other literature, is it acceptable to use words like this on the assumption that, even if they are not in the dictionary, people will recognise the meaning?

  • Demonstrable is the correct word, but you could avoid the whole issue and just reword it to say that the thing can be, or is capable of being, demonstrated. Oct 10, 2018 at 9:42

5 Answers 5


Don't use demonstratable.

The Corpus of Contemporary American English has 262 hits for demonstrable, and none for demonstratable. Google ngram shows a similar result:


  • 1
    Thou insists on a language that doth not change?
    – wersimmon
    Jun 11, 2013 at 14:41
  • 16
    @harbichidian No, I show that for this particular word, it hasn't changed.
    – F'x
    Jun 11, 2013 at 16:42

Demonstratable is not an English word, so shouldn't be used. People will probably know what you intended, just as they would if you talked about demonstratating the system; but they will never be certain whether you are joking or ignorant.

  • 3
    An English word is a word that can be used to communicate a concept to an English speaker. If you say this word, everyone will know what you mean, so in my book it qualifies. However, in my book you will also sound like a bit of a dumbass (as you clearly don't know the easier "demonstrable"), so use at your own risk.
    – T.E.D.
    Sep 12, 2011 at 15:11
  • @T.E.D.: I take your point, though I'm not sure I agree with it. But your phrasing is far too wide: there is no word that everyone will understand, as the questions show every day. And if anything used to communicate a concept to an English speaker is an English word, we don't need dictionaries, teachers, or (far more important) EL&U. Sep 12, 2011 at 20:44
  • 1
    Kind of confused by that comment. English dictionaries are descriptive of the language for those who might need to be informed about specific words they encounter. They generally aren't meant to be used as exclusive exhaustive lists of allowable lexemes for the language.
    – T.E.D.
    Sep 12, 2011 at 22:31

Demonstratable is recorded in the OED, with examples back to 1814; though it's far less common than demonstrable.

As for whether you'd get away with it in everyday usage, the answer's yes, because -able is a productive suffix in English, at least in informal usage: in other words, you can add '-able' to lots of verbs and create adjectives with the sense 'capable of being [x]-ed'.


The note attached on MW is to say that access to a word in their full dictionary (for which you need to pay a subscription) is offered for a limited time in their free dictionary - probably as a means of attracting purchasers of the full dictionary. It has nothing to do with validity of the word in question. You will note, however, that the entry for "demonstratable" is in fact the word "demonstrable", rather than an actual definition, albeit with a usage example of the former:

: demonstrable (easily demonstratable aural and visual proof — R.D.Darrell)

This says that "demonstratable" is a variant of "demonstrable" that has been recorded in use, but that "demonstrable" is the generally accepted form.

Whether or not you want to use the variant "demonstratable" is your own choice, and depends on your intended audience. Use of "demonstratable" may well annoy pedants, who will likely be turned off your work. If you happen to love the word "demonstratable", you may want to use it in order to popularise its use in the hope that it may one day become a widely accepted, and acceptable, word. If you simply want to communicate clearly and concisely, without distracting people's attention to whether or not you have used a word correctly, then use "demonstrable".


Personally, I remember using the word frequently in the past, in Australian English, of which now uses the word “demonstrable”. Same thing with “resault”, it is now “result”. It may be, that these were the “old ways” of writing the word in the UK English version but not the US English of which is different.

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