Lewis & Short

Sentīnas, ātis, adj., of or belonging to Sentinum (Sentis ap. Front. Colon. p. 124 Goes.; Σέντινον in Ptol. and Polyb.), a town of Umbria: ager, Liv. 10, 27, 1; 10, 30, 4; 10, 31, 12; for which, absol.: in Sentinate, Front. Strat. 1, 8, 3 Oud. N. cr.
Plur. subst.:
Sentīnātes, um, m., the inhabitants of Sentinum, Plin. 3, 14, 19, § 114.