/ Dictionary / Index E epiphenomenon: Meaning and Definition of Find definitions for: ep•i•phe•nom•e•non Pronunciation: (ep"u-fu-nom'u-non", -nun), [key] — pl. -na -nons. a secondary or additional symptom or complication arising during the course of a disease. any secondary phenomenon. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: epiphenomenon (Thesaurus) epiphenomenalism epiphloedal Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language