Relations of the type between *samьcь ‘male’ : *samica ‘female’ are not discussed together as word formation patterns in Slavic comparative grammars. Each type of noun is discussed separately with regard to its word formation pattern; i.e., the first one as regards the Proto-Slavic suffix *-ьcь, and the second one as regards the suffix *-ica. On the basis of an analysis of the type *samьcь : *samica in the Slavic appellative and partly in the onomastic lexicon as well, it is possible to show a word formation relationship must be acknowledged between the two due to the second member’s appurtenance and likely secondary, feminizing function. The relationship is probably non-derivational, like the one between *zelenъ (adj) → *zelenь (subst).