The Collaborative International Dictionary
Manganous
Manganous \Man"ga*nous\, a. (Chem.) Of, pertaining to, designating, those compounds of manganese in which the element has a lower valence as contrasted with manganic compounds; as, manganous oxide.
Manganous acid, a hypothetical compound analogous to sulphurous acid, and forming the so-called manganites.
Wiktionary
manganous
a. (context chemistry English) Containing manganese in its +2 oxidation state.
Usage examples of "manganous".
Among these activators are magnesium, manganous zinc, ferrous, cobaltous, and nickelous ions, as well as others.