Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ĕpīscŏpālis, e, adj. [episcopus], episcopal: solium, Prud. στεφ. 33.
Adv.: ĕpīscŏpālĭter, episcopally, Aug. Conf. 5, 13.