Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
artĭcŭlārĭus, a, um, adj. [articulus], of or pertaining to the joints: morbus, gout, Cato, R. R. 157, 7; Plin. 23 prooem.; 22, 13, 15, § 34.