Mercury or mercurial.
Mercury was the Roman equivalent of the Greek Hermes (see Herm). This fleet-footed messenger of the gods has given us the word mercury, a silver metallic element, which at room temperature is in liquid form, also called "quicksilver" because of the nature of its movement. In astrology, Mercury is the name given to the planet closest to the sun, around which it completes one revolution in 88 days. In botany, it refers to a genus of weedy plant. To describe someone as mercurial is to impart to the individual craftiness, eloquence, cunning, and swiftness, all attributes of the god. It can also simply mean quick or changeable in temperament, either from the nature of the god or the influence of the planet.