Lewis & Short

infĭtĭātor (infĭc-), ōris, m. [infitior], a denier, esp. one who denies a debt or refuses to restore a deposit: ille infitiator, Cic. de Or. 1, 37, 168; with fraudulentus, Sen. Ben. 3, 27: lentus, a bad debtor, Cic. Cat. 2, 10.