/ Dictionary / Index S seventieth: Meaning and Definition of Find definitions for: sev•en•ti•eth Pronunciation: (sev'un-tē-ith), [key] — adj. next after the sixty-ninth; being the ordinal number for 70. being one of 70 equal parts. —n. a seventieth part, esp. of one (). the seventieth member of a series. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: seventieth (Thesaurus) seventh-inning stretch seventy Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language