Originally: a kind of bituminous earth described by Pliny, said to have been used as a soil dressing and as a cosmetic (now historical). In later use usually: any of various kinds of carbonaceous clay or oil shale.
Early 17th century; earliest use found in Philemon Holland (1552–1637), translator. From classical Latin ampelītis bituminous earth used to preserve vines from insects (Pliny) from Hellenistic Greek ἀμπελῖτις of the vine (in ἀμπελῖτις γῆ, lit. ‘earth of the vine’, a bituminous earth sprinkled on the vine to destroy insects) from ancient Greek ἄμπελος vine + -ῖτις.