Lewis & Short

Sublăquĕum, i, n., a little town of the Æqui, in Latium, near which Nero had a country-seat, now Subiaco, Plin. 3, 12, 17, § 109; Tac. A. 14, 22.
Hence, Sublăcen-sis, e, adj., of or belonging to Sublaqueum: villa, that of Nero, near Sublaqueum, Front. Aquaed. 93: viae, constructed there by him, id. ib. 7; 14; 15.