noun
ElectronicsA thermionic valve having five electrodes.
‘The machine incorporates a pentode vacuum-tube driven as a cathode follower in a Class-A, unity-gain output stage.’- ‘Here is a compilation of some of the finest pentode audio tubes ever made.’
- ‘I agree with the assumption that building large pentodes is more difficult.’
Origin
Early 20th century from Greek pente ‘five’ + hodos ‘way’.
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