Entry 1 sense Webster, 1913 Retiarius · Re·ti·a·ri·us · IPA /ˌɹiʃiˈɛəɹi.əs/ 01 n. A gladiator armed with a net for entangling his adversary and a trident for despatching him. 1. A gladiator armed with a net for entangling his adversary and a trident for despatching him.(Rom.Antiq.)