Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Bacchānālis, e, adj. [Bacchus], relating to Bacchus, Bacchanalian: sacra, Val. Max. 1, 3, n. 1: festum = Bacchanalia, Macr. S. 1, 4; Aur. Vict. Caes. 3.