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.