ignitron definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a type of mercury-arc rectifier tube having a mercury-pool cathode and a single graphite anode: when a current is passed through an igniter rod into the pool, the mercury vapor is ionized and an arc starts between the cathode and anode: used in resistance welders, the control equipment for much high-energy research apparatus, etc.
Origin: igni(te) plush (elec)tron
ignitron definition by American Heritage Dictionary
A single-anode, mercury-vapor rectifier in which current passes as an arc between the anode and a mercury-pool cathode, used in power rectification.
Origin: igni(te) + -tron.