AQUINUM, ancient city of the Volsci, Italy, 7im. N.W. of Cassino. The pop. of the commune in 1931 was 3,176. Birth place of Juvenal and of the Emperor Pescennius Niger ; S. Thomas Aquinas was born in Roccasecca castle, 5m. to the north. It retains portions of walls, so-called temples, basilica and amphi theatre as well as the gatefvay (Porta S. Lorenzo) by which the Via Latina entered it. The 11th century Romanesque basilica, S. Maria Libera, now roofless, has Roman inscriptions built into it and near by, south of the town, is a triumphal arch with com posite capitals. (See E. Grossi, Aquinum [Rome, 5907].)