Lewis & Short

causĭfĭcor, āri, v. n. [causa-facio], to allege a cause, to make a pretext or pretence, to pretend (very rare): haut causificor quin eam Ego habeam, I offer no pretext against keeping her, Plaut. Aul. 4, 10, 25: blaterans atque causificans, App. M. 10, p. 242.