A nonmetallic chemical element (symbol As) with an atomic number of 33. / (countable) A single atom of this element. / Arsenic trioxide.

(chemistry) Of or containing arsenic with a valence of 5.

A military establishment for the storing, development, manufacturing, testing, or repairing of arms, ammunition, and other war materiel; an armoury.

(chemistry) Any salt or ester of arsenic acid. / (chemistry) The anion AsO₄³⁻.

(chemistry) of, related to, or derived from arsenic, especially in an oxidation state of three; arsenious

plural of arsenate

plural of arsenal

Of or pertaining to, or containing, arsenic.

Any drug or other substance containing arsenic.

plural of arsenical