\A*cet"y*lene\, n. (Chem.)
A gaseous compound of carbon and hydrogen, in the proportion
of two atoms of the former to two of the latter. It is a
colorless gas, with a peculiar, unpleasant odor, and is
produced for use as an illuminating gas in a number of ways,
but chiefly by the action of water on calcium carbide. Its
light is very brilliant. --Watts.