- the ancient Roman god of fire and metalworking, identified with the Greek Hephaestus.
- Military. a six-barrel, 20mm U.S. Army antiaircraft gun system mounted on an armored personnel carrier and first deployed in 1968.
- Astronomy. a hypothetical planet nearest the sun whose existence was erroneously postulated to account for perturbations in Mercury’s orbit.
- the Roman god of fire and metalworkingGreek counterpart: Hephaestus
- a hypothetical planet once thought to lie within the orbit of Mercury
god of fire and metal-work in Roman mythology, 1510s, from Latin Vulcanus, a word of Etruscan origin. Often with allusions to his lameness and the unfaithfulness of his wife, Venus. As the name of a hypothetical planet between Mercury and the Sun, it is attested from 1870. The Roman feast of Vulcanalia was on Aug. 23.
The Roman and Greek god of fire and metalworking; the blacksmith of the gods. He suffered bodily deformities and lameness. According to some stories, he was married to Venus, the goddess of love and beauty; in other stories, he was married to one of the three Graces. Vulcan was a son of Jupiter.