D defs.my
Entry 1 sense Webster, 1913

Hydromagnesite

/(hī`drō̇*măg"nē̇*sīt)/ · Hy·dro·mag·ne·site · IPA
01 n. A hydrous carbonate of magnesia occurring in white, earthy, amorphous masses.
  1. 1.
    A hydrous carbonate of magnesia occurring in white, earthy, amorphous masses.(Min.)