/ Dictionary / Index D decaffeinate: Meaning and Definition of Find definitions for: de•caf•fein•ate Pronunciation: (dē-kaf'u-nāt", -kaf'ē-u-), [key] — -at•ed, -at•ing. to extract caffeine from: to decaffeinate coffee. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: decaffeinate (Thesaurus) decaf decagon Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language