/ Dictionary / Index E eighty-ninth: Meaning and Definition of Find definitions for: eight•y-ninth Pronunciation: (ā'tē nīnth'), [key] — adj. next after the eighty-eighth; being the ordinal number for 89. being one of 89 equal parts. —n. an eighty-ninth part, esp. of one (). the eighty-ninth member of a series. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. eighty-niner eighty-one Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language