pho·​to·​tube ˈfō-tō-ˌtüb How to pronounce phototube (audio)
: an electron tube having a photoemissive cathode whose released electrons are drawn to the anode by reason of its positive potential

Word History

First Known Use

1930, in the meaning defined above

Time Traveler
The first known use of phototube was in 1930

Dictionary Entries Near phototube

Cite this Entry

“Phototube.” Dictionary, Merriam-Webster, Accessed 4 Oct. 2023.

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