electrontube

WordReference Random House Unabridged Dictionary of American English © 2026

elec′tron tube′, 

1. Electronics, Electricity an electronic device that consists, typically, of a sealed glass bulb containing two or more electrodes: used to generate, amplify, and rectify electric oscillations and alternating currents.Also called electronic tube. Cf. gas tube, vacuum tube. 

• 1920–25

Collins Concise English Dictionary © HarperCollins Publishers::

electron tube noun

1. an electrical device, such as a valve, in which a flow of electrons between electrodes takes place