in-dēbĭtus, a, um, adj., that is not owed, not due (poet. and post-class.): non indebita posco, I ask nothing that is not due to me, Verg. A. 6, 66: praemia, Ov. H. 16, 9.
Subst.: indēbĭtum, i, n., that which is not due, the performance or payment of which is not due: solvere, Dig. 12, 6, 65; Paul. Sent. 4, 3, 4; Gai. Inst. 3, 91 al.
Hence, adv.: indēbĭtē and indēbĭtō, without just cause, unduly (post-class.).