Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
irrītāmentum (inr-), i, n. [1. irrito], an incitement, incentive, provocative (not before the Aug. period, and most freq. in plur.; syn.: incitamentum, invitamentum, illecebra): irritamentis iras militum acuere, Liv. 40, 27: certaminum equestrium, id. 30, 11: gulae, Sall. J. 89, 7: invidiae, Tac. A. 3, 9: pacis, id. Agr. 20; cf.: belli, non pacis, Just. 31, 7, 9: opes, inritamenta malorum, Ov. M. 1, 140: Veneris languentis, Juv. 11, 16.
Of things, a provocation, obstruction acting as a dam: (fluvius) insulis inpactus, totidem incitatus inritamentis, Plin. 5, 9, 10, § 54.