Lewis & Short

rĕpulsōrĭus, a, um, adj. [repello], driving or forcing back, repulsory: cohortes, Amm. 24, 4, 7.
As subst.: rĕpulsōrĭum, ii, n., a means of driving back, Ambros. in Psa. 118, Serm. 4, § 15 fin.