Can adjectives in -ius be suffixed with -ia to form substantives?

[Michael Zwingli]

Good afternoon (as it is here),
I have occasion to ask about how such substantives as patria, rēgia, and gōgrāvia are derived from their respective adjectives: patrius, rēgius, and gōgrāvius. Of course, neither the suffix -a nor -ā is suffixed to adjectives to form nominals. If such nouns are arrived at by substantivization of one of the declentives of such -ius adjectives, it would have to be of either the nominative singular feminine or the nominative plural neuter, both of which seem like highly unorthodox ways of substantivizing adjectives (the orthodox method, of course, is to use the nominative singular neuter form). I cannot rationalize why the feminine declentive would be used to substantivize an adjective, and to use the plural form seems absurd. I have not thought that adjectives in -ius could take suffixation with -ia, and of course, -ia usually forms abstract nouns, not substantives, but that seems to be the only alternative remaining to explain this. I have not been able to find any authoritative information on this topic from extant sources. May I have some feedback about this from all of you bright people? Thanks much.

 

[Pacifica]

Patria and regia arose from the ellipsis of terra and domus respectively. This is the first time I've come across gogravia. This one may have come from an ellipsis of potestas, though not necessarily. It's a medieval word and could have been formed by some kind of analogy without any rule being exactly followed.

 

[Michael Zwingli]

Ah, so the pre-elliptical terms would have been: terra patria and domus regia? That makes sense, and clarifies the matter. You're right, Pax, gogravia is medieval, and a latinization of a Germanic term, as well. All bets seem to have been off in word formation after the Late Latin period.

 

[Pacifica]

Ah, so the pre-elliptical terms would have been: terra patria and domus regia?

Yes.

 

[Quasus]

Of course, -i- is irrelevant. For instance, bubula (sc. caro) is "beef".