Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Pīnārĭus, i, m., the name of a Roman sacerdotal family. The Pinarii and Potitii presided at the celebration of certain sacred rites in honor of Hercules, originally instituted by Evander and re-established by Romulus. The Pinarii having on one occasion arrived after the exta were consumed, it was ordained that, as long as the family remained, they should not partake of the exta, Liv. 1, 7, 12 sqq.; 9, 29, 9 sqq.; Macr. S. 1, 12, 28; Fest. p. 237 Müll.
Hence, Pīnārĭus, a, um, adj., of or belonging to the Pinarii, Pinarian: Pinaria domus, Verg. A. 8, 270: Pinaria gens, Aur. Vict. Orig. Gent. R. 8: Pinaria tribus, Fest. s. v. popilia, p. 233 Müll.