\Chlo"rous\, a. [See {Chlorine}.]
1. Of, pertaining to, or derived from, chlorine; -- said of
   those compounds of chlorine in which this element has a
   valence of three, the next lower than in chloric
   compounds; as, chlorous acid, {HClO2}.

2. (Chem. Physics) Pertaining to, or resembling, the
   electro-negative character of chlorine; hence,
   electro-negative; -- opposed to basylous or zincous.
   [Obs.]