/ Dictionary / Index R runner's high: Meaning and Definition of Find definitions for: run'ner's high' Pronunciation: [key] a state of euphoria experienced during prolonged running or other forms of aerobic, sustained exercise, attributed to an increase of endorphins in the blood. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. runner foot runner's knee Related Content Daily Word Quiz: bungled Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language