arsenious

from WordNet (r) 3.0 (2006)

arsenious
    adj 1: relating to compounds in which arsenic is trivalent

from The Collaborative International Dictionary of English v.0.48

Arsenious \Ar*se"ni*ous\, a. [Cf. F. ars['e]nieux.]
   1. Pertaining to, consisting of, or containing, arsenic; as,
      arsenious powder or glass.
      [1913 Webster]

   2. (Chem.) Pertaining to, or derived from, arsenic, when
      having an equivalence next lower than the highest; as,
      arsenious acid.
      [1913 Webster]