D defs.my
Entry 2 senses Webster, 1913

Arsenious

· Ar·se·ni·ous · IPA
01 a. Pertaining to, consisting of, or containing, arsenic; as, arsenious powder or glass.
  1. 1.
    Pertaining to, consisting of, or containing, arsenic; as, arsenious powder or glass.
  2. 2.
    Pertaining to, or derived from, arsenic, when having an equivalence next lower than the highest; as, arsenious acid.(Chem.)