a vacuum tube containing three elements, usually anode, cathode, and control grid.
Origin of triode
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
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 It has been replaced by the transistor
any electronic device, such as a thyratron, having three electrodes
Word Origin for 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
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.