arsenic -
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
arsenic -
Of, or containing arsenic with a valence of 5.
Wikipedia
Arsenic is the chemical element that has the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic was first documented by Albertus Magnus in 1250. Arsenic is a notoriously poisonous metalloid.
OmegaWiki Dictionary
Ω
arsenic 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.