- cathode (n.)
- 1834, from Latinized form of Greek kathodos "a way down," from kata- "down" (see cata-) + hodos "way" (see cede). 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.
- electrode (n.)
- "one of the two ends of an open electrical circuit," 1834, coined by English physicist and chemist Michael Faraday (1791-1867) from electro- + Greek hodos "way" (see cede) on the same pattern as anode, cathode.
- tube (n.)
- 1610s, from Middle French tube (15c.), from Latin tubus "tube, pipe," of unknown origin. The London subway was christened the Twopenny Tube (H.D. Browne, in the "Londoner" of June 30, 1900) before it even opened; tube for "cylindrical railway tunnel" is attested from 1847. The meaning "TV as a medium" is from 1959, short for cathode ray tube or picture tube. Tube top as a women's clothing style is attested from 1972. Tube steak is attested from 1963 as "frankfurter," slang meaning "penis" is recorded by mid-1980s.
