/ Dictionary / Index E ephemerous: Meaning and Definition of Find definitions for: e•phem•er•ous Pronunciation: (i-fem'ur-us), [key] — adj. ephemeral. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ephemeropteran Ephes. Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language