improsper (inpr-), spera, erum, adj. 2. in-prosper, unfortunate, unprosperous (post-Aug.): fortuna, Tac. A. 3, 24: moles insidiarum, id. ib. 14, 65: multa claritudine generis sed improspera, id. ib. 4, 44.

—Adv.: improsperē, unfortunately: cessit, Col. 1, 1, 16; Tac. A. 1, 8; Gell. 9, 9, 12.