mercury Definition
mercurynoun 1. (symbol Hg, atomic number 80) a dense, silvery-white metallic element, and the only metal that is liquid at room temperature. Also called quicksilver.
2. astron.The closest planet to the Sun.
Etymology: 14c: from Latin
Mercurius, the Roman god Mercury, god of merchandise, theft and eloquence, and messenger of the gods, probably from
merx merchandise.