D defs.my
Entry 1 sense Webster, 1913

Anorthite

/ăn-ôr'-thītˌ/ · A·nor·thite · IPA /ænˈɔrθˌaɪt/
01 n. A mineral of the feldspar family, commonly occurring in small glassy crystals, also a constituent of some igneous rocks. It is a lime felds…
  1. 1.
    A mineral of the feldspar family, commonly occurring in small glassy crystals, also a constituent of some igneous rocks. It is a lime feldspar. See Feldspar. See: Feldspar