/ Dictionary / Index T thermionic current: Meaning and Definition of Find definitions for: therm'ion'ic cur'rent Pronunciation: [key] an electric current produced by the flow of thermions. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thermion thermionics Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language