Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

perpĕtŭālis, e, adj. [perpetuus], that holds everywhere, universal, general (a word formed by Quint. as a transl. of the Gr. καθολικός, joined with universalis), Quint. 2, 13, 14.
Hence, adv.: perpĕtŭālĭter, permanently (opp. temporaliter), Arn. in Psa. 121.