cathode (n.)

"negative pole of an electric current," 1834, from Latinized form of Greek kathodos "a way down," from kata "down" (see cata-) + hodos "a way, path, track, road," a word of uncertain origin. Proposed by the Rev. William Whewell (1794-1866), English polymath, and published by English chemist and physicist Michael Faraday (1791-1867). So called from the path the electric current was supposed to take. Related: Cathodic; cathodal. Cathode ray first attested 1880, but the phenomenon known from 1859; cathode ray tube is from 1905.