Lewis Short
(adjective) : in-sŭbĭdus, a, um
* Stupid, foolish (post-class.), Gell. 19, 9, 9: vultus,Lampr. Commod. 17, 3: scitamenta,Gell. 18, 8, 1.— Comp., Gell. 6, 1, 2; 13, 20, 4.— Adv.: in-sŭbĭdē, stupidly, foolishly (post-class.): aliquid non insubide introspicere,Macr. S. 7, 14, § 3: disserere,Gell. 1, 2, 4.
Charlton T. Lewis, Charles Short, A Latin Dictionary