Lewis Short
(adj.adv.) : ūsŭālis, e, adj.2. usus.
* That is for use, fit for use (post-class.): mancipia,Dig. 39, 4, 16, § 3.—*
* Usual, common, ordinary: sermo,Sid. Ep. 4, 10; Ambros. in Luc. 7, n. 150.—Hence, adv.: ūsŭālĭter, in the usual manner (late Lat.), Cassiod. Var. 2, 39.
Charlton T. Lewis, Charles Short, A Latin Dictionary