/ Dictionary / Index T thyristor: Meaning and Definition of Find definitions for: thy•ris•tor Pronunciation: (thī-ris'tur), [key] — n. Electronics. a semiconductor device having two stable states, used as an electronic switch. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thyratron thyro- Related Content Daily Word Quiz: abscond Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language