1610s, from Middle French tube (mid-15c.), from Latin tubus "tube, pipe," of unknown origin. The London subway was christened the Twopenny Tube before it even opened (H.D. Browne, in the "Londoner" of June 30, 1900); 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. Tubing as a recreational pastime is recorded from 1975.
tube (tōōb, tyōōb)
A hollow cylinder, especially one that conveys a fluid or functions as a passage.
An anatomical structure or organ having the shape or function of a tube; a duct.