/ Dictionary / Index B beta receptor: Meaning and Definition of Find definitions for: be'ta recep"tor Pronunciation: [key] — Biochem., Physiol. Biochem.,Physiol. a site on a cell, as of the heart, that, upon interaction with epinephrine or norepinephrine, controls heartbeat and heart contractability, vasodilation, smooth muscle inhibition, and other physiological processes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. beta ray beta rhythm 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