D defs.my
Entry 1 sense Webster, 1913

Lias

/(lī"as)/ · Li·as · IPA /ˈliəs/
01 n. The lowest of the three divisions of the Jurassic period; a name given in England and Europe to a series of marine limestones underlying th…
  1. 1.
    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.(Geol.) See: Geology