[ trahy-ohd ]

  1. a vacuum tube containing three elements, usually anode, cathode, and control grid.

Compare Meanings

Click for a side-by-side comparison of meanings. Use the word comparison feature to learn the differences between similar and commonly confused words.

Origin of triode

First recorded in 1920–25; tri- + (electr)ode

Words Nearby triode Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

British Dictionary definitions for triode


/ (ˈtraɪəʊd) /

  1. an electronic valve having three electrodes, a cathode, an anode, and a grid, the potential of the grid controlling the flow of electrons between the cathode and anode. It has been replaced by the transistor

  2. any electronic device, such as a thyratron, having three electrodes

Origin of triode

C20: tri- + electrode

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for triode


[ trīōd′ ]

  1. An electron tube used mostly for signal amplification, consisting of a cathode and anode (or plate) as in a diode, and an intervening wire mesh called the control grid. With little voltage on the grid, large currents can flow between the cathode and plate, but small variations in the voltage on the grid cause large variations in this current, allowing for large amplification of a signal applied to the control grid. See also pentode tetrode.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.