bituminous

the word 'bituminous' is formed from the latin noun 'bitumen', which referred to natural asphalt or mineral pitch. the suffix '-ous', of latin origin through old french, is a common adjectival suffix in english meaning 'abounding in' or 'characterized by'. thus, the literal construction is 'full of bitumen'. the latin 'bitumen' itself is of uncertain, possibly celtic, origin, entering english in the late medieval period to describe the sticky, flammable hydrocarbon substance. the adjective 'bituminous' directly describes materials, most commonly coal or shale, that contain or are impregnated with this tarry substance.

Structure: bitumen + ous bitumen (latin, meaning 'mineral pitch, asphalt') + ous (latin suffix via french and english, meaning 'full of, having the qualities of').