/ Dictionary / Index D decimate: Meaning and Definition of Find definitions for: dec•i•mate Pronunciation: (des'u-māt"), [key] — -mat•ed, -mat•ing. to destroy a great number or proportion of: The population was decimated by a plague. to select by lot and kill every tenth person of. to take a tenth of or from. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: decimate (Thesaurus) decimal system décime* 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