Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
quintārĭus, a, um, adj. [quintus], of or belonging to five, containing five: quintarius numerus, i. e. five sixths, taking the number six as a whole, Vitr. 3, 1: limes, that encloses five centuriae, Hyg. Limit. p. 158 Goes.