Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
flŭvĭālis, e, adj. [fluvius], of or belonging to a river, river-, fluvial: undae, Verg. A. 9, 70; Ov. M. 1, 82: aqua, Col. 6, 22 fin.: harundo, Verg. G. 2, 414: harena, Pall. Oct. 17 fin.: lupus, a fish, Col. 8, 16, 4; v. lupus.