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 (see Exodus). Proposed by the Rev. William Whewell, English polymath, and published by English chemist and physicist Michael Faraday. 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.