In Roman mythology, Mercury, also known as Hermes in the Greek pantheon, was primarily known as a fleet-footed messenger. He was also a god of commerce and invention, and escorted the souls of the departed to Hades. He was the son of Maia and Jupiter. According to legend, Mercury was the one to invent the lyre, such as the one used by Sailor Mercury to perform Mercury Aqua Rhapsody.
Mercury is usually associated with the mind and the inward self; it can symbolize intellect, memory, perception, or travel. Mercury is associated with Wednesday. Dante Alighieri associated Mercury with the art of dialectic.
In Chinese astrology, Mercury is ruled by the element water. In Indian astrology, Mercury represents communication.
- In the Japanese calendar, Wednesday is called "suiyoubi" (水曜日), meaning "the day of water."