Lewis & Short

incontāmĭnābĭlis, e, adj. [2. in-contamino], that cannot be defiled (eccl. Lat.): Deus, Tert. adv. Marc. 4, 14; Aug. Conf. 7, 3.
Adv.: incontāmĭnābĭlĭter, without defilement, Aug. de Gen. ad Litt. c. ult.