Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
in-dēfĭcĭens, entis, adj., unfailing (eccl. Lat.): decor, Tert. adv. Jud. 14.
Hence, adv.: indēfĭcĭenter, continually, incessantly (eccl. Lat.), Aug. Conf. 12, 11.