from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. An electron tube from which all or most of the gas has been removed, permitting electrons to move with low interaction with any remaining gas molecules.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. An electrical device containing a heated filament inside an evacuated container (generally a glass tube) and used to produce rectification (a diode vacuum tube), amplification or other functions.

from the GNU version of the Collaborative International Dictionary of English

  • n. any tube used in electronic devices, containing a vacuum and used to control the flow of electrons in a circuit, as a vacuum diode, triode, tetrode, or pentode.

from The Century Dictionary and Cyclopedia

  • n. A sealed glass tube employed to examine the effects of a discharge of electricity through air or other gas rarefied or exhausted to the required degree.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope


Sorry, no etymologies found.


Sorry, no example sentences found.

Wordnik is becoming a not-for-profit! Read our announcement here.


Log in or sign up to get involved in the conversation. It's quick and easy.