mercury meaning and definition

MERCURY noun

Definition of mercury (noun)

1. a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures
   • synonyms: atomic number 80, Hg, hydrargyrum, quicksilver
2. (Roman mythology) messenger of Jupiter and god of commerce; counterpart of Greek Hermes
3. the smallest planet and the nearest to the sun
4. temperature measured by a mercury thermometer
   • "the mercury was falling rapidly"