/ Dictionary / Index T twentieth: Meaning and Definition of Find definitions for: twen•ti•eth Pronunciation: (twen'tē-ith, twun'-), [key] — adj. next after the nineteenth; being the ordinal number for 20. being one of 20 equal parts. —n. a twentieth part, esp. of one (). the twentieth member of a series. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: twentieth (Thesaurus) twelve-tone technique Twentieth Amendment Related Content Daily Word Quiz: blithesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language