Lewis & Short

dē-fēnĕro, āvi, ātum, 1, v. a., to involve in debt, Ambros. de Tobia 9.
Hence, P. a.: dēfēnĕrātus, a, um, overwhelmed by debt, exhausted by usury (post-class.): plurimis creditoribus defeneratus, App. Mag. p. 322, 21; Ambros. Ep. 7, 1.