magnesium hydroxide

from WordNet (r) 3.0 (2006)

magnesium hydroxide
    n 1: a white crystalline powder used chiefly in medicines

from The Collaborative International Dictionary of English v.0.48

magnesium hydroxide \magnesium hydroxide\ n. (Chem.)
   A slightly alkaline chemical substance, {Mg(OH)2}, the active
   principle in the antacid milk of magnesia, also used as a
   laxative.
   [WordNet 1.5]