in-dŭbĭus, a, um, adj., not doubtful, certain (post-Aug.): innocentia plurimorum, Tac. A. 14, 45: exempla, Quint. 5, 13, 24. Hence, adv.: indŭbĭē, doubtlessly, Cassiod. Fragm. in Auct. Class. Tom. 3, 355 Mai.