[bi.tu.men] n [ME bithumen mineral pitch, fr. L bitumin-, bitumen] (15c) 1: an asphalt of Asia Minor used in ancient times as a cement and mortar
2: any of various mixtures of hydrocarbons (as tar) often together with their nonmetallic derivatives that occur naturally or are obtained as residues after heat-refining natural substances (as petroleum); specif: such a mixture soluble in carbon disulfide -- bi.tu.mi.ni.za.tion n -- bi.tu.mi.nize vt