Lewis & Short

hirpus or irpus, in the Sabine lang., the wolf, Paul. ex Fest. p. 106, 1 Müll.; Serv. ad Verg. A. 11, 785.

irpus, i, m. [Sabine], a wolf: (lupus) quem irpum dicunt Samnites, Paul. ex Fest. p. 106 Müll.; Serv. ad Verg. A. 11, 785.