Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

Mopsŏpĭus, a, um, adj., = Μοψόπιος, of or belonging to Mopsopia (Μοψοπία, an old name of Attica), Mopsopian, Attic, Athenian (only poet.): Mopsopius juvenis, i. e. Triptolemus, Ov. M. 5, 661: muri, i. e. of Athens, id. ib. 6, 423: urbs, Athens, id. H. 8, 72.
As subst.: Mopsŏpĭa, ae, f.: Mopsopia tota, i. e. all Athens or all Attica, Sen. Hippol. 121; 1276.