Lewis & Short

pīlānus, i, m. [pilum], a triarius, one of the soldiers forming the third rank in battle: pilani pilis pugnantes, Paul. ex Fest. p. 204 Müll.: pilani triarii quoque dicti quod in acie tertio ordine extremis subsidio deponebantur, Varr. L. L. 5, § 89 Müll.; Ov. F. 3, 129.