from
The Collaborative International Dictionary of English v.0.48
Chlorous \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}.
[1913 Webster]
2. (Chem. Physics) Pertaining to, or resembling, the
electro-negative character of chlorine; hence,
electro-negative; -- opposed to basylous or zincous.
[Obs.]
[1913 Webster]