A while back, when we learnt how to remove the caffeine from coffee beans, we coined the word decaffeinated to denote coffee that's had the caffeine taken out.

I've noticed more and more recently, as decaffeinated coffee has increased in popularity and availability, that the term caffeinated has crept in to describe coffee that has not been decaffeinated.

Does this make sense? The -ate suffix surely denotes an active process that is applied to something. So one can decaffeinate by removing the caffeine; but unless one is attempting to create some kind of super-coffee, one wouldn't ever caffeinate it. One would only leave it unprocessed. It doesn't undergo caffeination.

If we applied the same construction to other terms, we'd get outright nonsense. I haven't had a heart attack; does that mean I'm fibrillated? Nor have I been beheaded recently; am I thereby capitated?

The Ngram graph for this looks interesting. It seems that caffeinated came in some time after decaffeinated, so presumably is a back formation. But bizarrely, caffeinated seems to have overtaken its more etymologically respectable cousin in the last few years! Why on earth would that be?

UPDATE: it's been pointed out in comments below that decaffeinated often gets abbreviated to decaf, and that if you combine these terms, decaf(feinated) is still winning the race.

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    That would be a guess, but one does not have to state every day that someone still has a head on his shoulders and is therefore "capitated". Everyone drinks coffee, however, and when we want to state that we need a regular coffee, there is a linguistic impulse to form the opposite by simply removing the negative prefix "de", even though the resulting word has some difference in meaning as you noted
    – Vilmar
    Dec 10, 2014 at 9:59
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    Caffeinated energy drinks make perfect sense, and a lot of those Ngram hits are probably false hits referring to other stuff with added caffeine. Part of the reason why decaffeinated has dropped is probably also that the shortened decaf has eclipsed it. If you put decaf and decaffeinated together against caffeinated, decaf(feinated) is still more common. Plus, the only alternative would be undecaffeinated, which is just atrocious. Dec 10, 2014 at 10:08
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    Coffee has been (gloriously) caffeinated by Mother Nature, bless her.
    – Marv Mills
    Dec 10, 2014 at 13:40
  • It's easier to say than nondecaffeinated and less troublesome.
    – pazzo
    Dec 10, 2014 at 18:11
  • My first comprehension of the term only after reading the title was that the word would mean the person is caffeinated by drinking too much coffee, like toxicated.
    – Neeku
    Dec 11, 2014 at 1:35

3 Answers 3


While I don't discount your question entirely, I should warn you to be careful interpreting the data. At least part of the rise of caffeinated could be due to the recent popularity of caffeinated drinks, whose caffeine content may be artificially introduced. I think we can agree that the use of caffeinated to describe the result of artificial production processes is uncontroversial.

However, "naturally caffeine-bearing coffee" isn't a very convenient phrase. It seems logical to introduce an antonym to decaffeinated through back-formation by dropping the de- prefix, even if it doesn't make complete etymological sense.

  • There's also caffeinated candy, caffeinated gum, and even caffeinated soap: thinkgeek.com/product/5a65.
    – Nicole
    Dec 10, 2014 at 17:44
  • And caffeinated shampoo. Which is not even considered geeky.
    – skymningen
    Jan 7, 2015 at 13:54

You're right.

It's a logical inconsistency that 'caffeinated' can mean "containing the natural amount of caffeine" as well as "with caffeine added".

English has lots and lots of logical inconsistencies (as, I'm given to understand, do other languages).

For example, inflammable means flammable.

The words inflammable and flammable both have the same meaning, ‘easily set on fire’. This might seem surprising, given that the prefix in- normally has a negative meaning (as in indirect and insufficient), and so it might be expected that inflammable would mean the opposite of flammable, i.e. ‘not easily set on fire’. In fact, inflammable is formed using a different Latin prefix in-, which has the meaning ‘into’ and here has the effect of intensifying the meaning of the word in English. Flammable is a far commoner word than inflammable and carries less risk of confusion.

If you're looking for strict logical consistency and regularity then language is probably not the right place to look.

On the up-side, it's a gift to observational comedy.

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    It should be out that "flammable" was only "popularized" in the 50s when US federal transport regulations changed to require that term to be posted on trucks carrying inflammable materials. Prior to that, if it existed at all, "flammable" was quite rare. New/"revived" English words can "pop up" into common use quite rapidly when the need arises.
    – Hot Licks
    Dec 10, 2014 at 12:54

The distinction is needed when the two options are about equally likely. We don't need to specify that everyone with a head is "capitated" because it's safe to assume that someone has a head unless we're told otherwise. However, caffeinated and decaffeinated coffee are both so common that you can't necessarily assume that coffee has caffeine unless you're told that it does, and you can't assume that it doesn't have caffeine unless you're told that it doesn't.

You could compare this to what happened with telephone terminology. First, we just had telephones; then we had telephones and mobile/cellular phones; then cell phones became so common that we had to start calling non-cellular phones home phones or landline phones in order to make the difference clear.

  • The OP is not denying that there is now a need for a term for caffeine-containing coffee; the question is whether caffeinated is a good term for that purpose.
    – jsw29
    Nov 30, 2023 at 17:58

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