Art, either Dada or in its tradition, which rejects conventional theories and forms ? techniques, materials, and means of display. Marcel Duchamp (French-American, 1887-1968) is credited with introducing the term c. 1914, and its spirit is summed up in his attempt to exhibit a urinal, Fountain of 1917, as well as in L.H.O.O.Q. ? a reproduction of the Mona Lisa (La Joconde) on which he drew a mustache in 1919.