lias Meaning, Definition & Usage

Li"as noun
Etymology
Cf. F. lias, fr. liais sort of limestone, OF. also liois; perh. of Celtic origin, cf. Armor. liach, leach, a stone, Gael. leac, W. llech. Cf. Cromlech.
Definitions
  1. (Geol.) The lowest of the three divisions of the Jurassic period; a name given in England and Europe to a series of marine limestones underlying the Oölite. See the Chart of Geology.

Webster 1913