Definition of pentode in English:

pentode

noun

Electronics
  • A thermionic tube having five electrodes.

    • ‘I agree with the assumption that building large pentodes is more difficult.’
    • ‘Here is a compilation of some of the finest pentode audio tubes ever made.’
    • ‘The machine incorporates a pentode vacuum-tube driven as a cathode follower in a Class-A, unity-gain output stage.’

Origin

Early 20th century: from Greek pente five + hodos way.

Pronunciation:

pentode

/ˈpentōd/