adj. Containing manganese in its +2 oxidation state.
the GNU version of the Collaborative International Dictionary of English
adj. Of, pertaining to, designating, those compounds of manganese in which the element has a lower valence as contrasted with manganic compounds.
The Century Dictionary and Cyclopedia
Containing manganese: in chemistry, specifically applied to compounds in which each manganese atom is regarded as having a maximum quantivalence of two. Compare manganic.
Word Usage
"The details of the method are as follows: A solution of manganous sulphate slightly stronger than No. 1 is prepared."