Lewis & Short

2. mentĭo, ire, 4, v. n. (archaic collat. form of mentior, Prisc. 8, 6, 29, p. 799 P.): te mentire spirito sancto, v. l. for mentiri, Vulg. Act. 5, 3; for mentitus, pass. part., v. mentior fin., and cf. Neue, Formenl. 2, p. 297 sq.