diode

noun

Etymology: From di- (“two”) + -ode. Learned formation, coined by William Henry Eccles in 1919, after Ancient Greek δίοδος (díodos, “passage through”), which however is formed not with δι- (di-, “two”) but with δια- (dia-, “through”).

1. An electronic device that allows current to flow in one direction only; used chiefly as a rectifier.

   “I propose to give the name diode to a tube with two electrodes.”

   “If a crystal or a diode is used, the amplifier-voltmeter combination may be used with an amplitude-modulated source; or with a c-w source, the detector may be connected to a microammeter or galvanometer as an indicating device.”