/ Dictionary / Index E ephemeropteran: Meaning and Definition of Find definitions for: e•phem•er•op•ter•an Pronunciation: (i-fem"u-rop'tur-un), [key] — adj. belonging or pertaining to the insect order Ephemeroptera, comprising the mayflies. —n. ephemerid. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ephemeropteran (Thesaurus) ephemeron ephemerous 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