/ Dictionary / Index R rheotaxis: Meaning and Definition of Find definitions for: rhe•o•tax•is Pronunciation: (rē"u-tak'sis), [key] — n. Biol. oriented movement of an organism in response to a current of fluid, esp. water. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rheostat rheotron 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