a vacuum tube in which the cathode is heated electrically to cause the emission of electrons by thermal agitation.
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Also called hot-cathode tube.
Origin of thermionic tube
First recorded in 1925–30
Words nearby thermionic tube
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020
Scientific definitions for thermionic tube
[ thûr′mī-ŏn′ĭk ]
An electrical component, typically an electron tube, through which electric current flows via the emission of thermions from a heated cathode.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.