Lewis & Short

Oppĭus, i, m.; Oppĭa, ae, f., the name of a Roman gens.

    1. 1. C. Oppius, a friend of Cœsar, Cic. Att. 4, 16, 14 al.
    2. 2. L. Oppius, a Roman knight, Cic. Fl. 13, 31.
    3. 3. P. Oppius, a quœstor, defended by Cicero; v. the fragm. in Orell. p. 444.
      In fem.: Oppia, the wife of L. Mindius, Cic. Fam. 13, 28, 2; v. also Juv. 10, 220 Jan.; id. 10, 322.
      Hence, Oppĭus, a, um, adj., of or belonging to an Oppius, Oppian: Oppia lex, proposed by the people’s tribune, C. Oppius, against women’s extravagance in dress, Liv. 34, 1, Tac. A. 3, 33; 34: Oppius mons, one of the summits of the Esquiline Hill, Varr. L. L. 5, § 50 Müll.; Fest. s. v. septimontium, pp. 340 and 348 Müll.; cf. Becker’s Antiq. 1, pp. 521, 534.