Lewis Short
(adj.Adj.) : subsĭdĭārĭus, a, um, adj.id.; in milit. lang.
* Of or belonging to a reserve, reserve-, subsidiary.
* Lit.
* Adj. (class.): cohortes,Caes. B. C. 1, 83; Liv. 9, 27; Tac. A. 1, 63: acies, Auct. B. Afr. 59, 2: naves, Auct. B. Alex. 14, 3.
* Transf., in gen., out of the military sphere, serving for support, subsidiary: palmes, = resex,Col. 4, 24, 13 and 16.
* Esp.: actio, jurid. t. t.,a form of action by which the ward seeks compensation from the magistrate who has given him an improper guardian,Dig. 27, 8, 1 pr.; cf. Cod. Just. 5, 75, 1 and 5.— Hence, adverb.: subsidiaria agere,to institute such an action,Dig. 27, 8, 1, § 4.
Charlton T. Lewis, Charles Short, A Latin Dictionary