A toxic metalloid element with symbol As and atomic number 33, existing in several allotropic forms, that occurs principally in realgar and orpiment and as the free element. It is used in semiconductors, lead-based alloys, and high temperature brasses.
a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide and weed killer
a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys; found in arsenopyrite and orpiment and realgar
a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer
