Lewis & Short

in-spērans, ntis, adj. (usually in the oblique cases), not hoping, not expecting, contrary to one’s hopes or expectations (class.): insperanti mihi, sed valde optanti cecidit, ut, Cic. de Or. 1, 21, 96: quibus tu salutem insperantibus reddidisti, id. Marc. 7, 21: insperante hoc atque invito Pamphilo, Ter. And. 3, 4, 24; Cat. 107, 5.
In nom.: aetas, Inscr. ap. Grut. 1133, 15.