thermionic valve

noun

, British.

1. vacuum tube.

thermionic valve

noun

1. an electronic valve in which electrons are emitted from a heated rather than a cold cathode

Word History and Origins

Origin of thermionic valve¹

First recorded in 1915–20

Example Sentences

I have even made an attempt to understand the mystery that is called the Thermionic Valve.

From Project Gutenberg