# triode

> English word · Noun · IPA /ˈtɹaɪ.əʊd/ · frequency rank #70,343

## Definitions
1. A thermionic valve containing an anode, a cathode, and a control grid; small changes to the charge on the grid control the flow from cathode to anode, which makes amplification possible.

## Etymology
Etymology tree
Proto-Indo-European *tréyes
Proto-Italic *trēs
Latin trēsder.
Latin tri-der.
English tri-
Proto-Indo-European *sed-der.
Proto-Indo-European *sodós?
Proto-Hellenic *hodós
Ancient Greek ὁδός (hodós)bor.
English -ode
English triode
From tri- + -ode.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/triode