/ Dictionary / Index R refractory period: Meaning and Definition of Find definitions for: refrac'tory pe"riod Pronunciation: [key] — Physiol. Physiol. a short period after a nerve or muscle cell fires during which the cell cannot respond to additional stimulation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. refractory refrain 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