/ Dictionary / Index R rheotropism: Meaning and Definition of Find definitions for: rhe•ot•ro•pism Pronunciation: (rē-o'tru-piz"um), [key] — n. the effect of a current of water upon the direction of plant growth. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rheotron rhesus Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language