Manganous /(?)/

Man·ga·nous

Manganous

a.
  1. Of, pertaining to, designating, those compounds of manganese in which the element has a lower valence as contrasted with manganic compounds; as, manganous oxide. (Chem.)

Phrases & Compounds
Manganous acid
a hypothetical compound analogous to sulphurous acid, and forming the so-called manganites.