Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
auxĭlĭārĭus (AVXSILIARIVS, Corp. Inscr. III. 4753), a, um, adj. [auxilium], bringing help, aiding, auxiliary (less freq. than the preceding): magis consiliarius amicus quam auxiliarius, Plaut. Truc. 2, 1, 6.
In milit. lang.,