/ Thesaurus / T Synonyms of thermionic valve Find synonyms for: Noun1. tube, vacuum tube, thermionic vacuum tube, thermionic tube, electron tube, thermionic valve, electronic deviceusage: electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelopeWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: candor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language