Mercurius (mer-kû'ri-ŭs), identical with the Greek Hermes (the speaker). One of the heathen deities fabled to be the son of Jupiter and Maia. He was supposed to preside over eloquence and merchandise, and to be the messenger of the gods. Barnabas and Paul were taken by the people at Lystra for Jupiter and Mercury. Acts 14:11-13. Ovid has a story of these two deities wandering in the adjacent country of Phrygia.