\Bi*tu"men\, n. [L. bitumen: cf. F. bitume. Cf.
{B['e]ton}.]
1. Mineral pitch; a black, tarry substance, burning with a
   bright flame; Jew's pitch. It occurs as an abundant
   natural product in many places, as on the shores of the
   Dead and Caspian Seas. It is used in cements, in the
   construction of pavements, etc. See {Asphalt}.
2. By extension, any one of the natural hydrocarbons,
   including the hard, solid, brittle varieties called
   asphalt, the semisolid maltha and mineral tars, the oily
   petroleums, and even the light, volatile naphthas.