/ Dictionary / Index C centennial: Meaning and Definition of Find definitions for: cen•ten•ni•al Pronunciation: (sen-ten'ē-ul), [key] — adj. pertaining to, or marking the completion of, a period of 100 years. pertaining to a 100th anniversary. lasting 100 years. 100 years old. —n. a 100th anniversary or its celebration; centenary. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: centennial (Thesaurus) centenionalis Centennial State Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language