definition of
mercury

[1] #1 mercury n. [quicksilver, hydrargyrum, Hg, atomic number 80] a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures. wn

[2] #2 mercury n. [Mercury] (Roman mythology) messenger of Jupiter and god of commerce; counterpart of Greek Hermes. wn

[3] #3 mercury n. [Mercury] the smallest planet and the nearest to the sun. wn

[4] #4 mercury n. temperature measured by a mercury thermometer; "the mercury was falling rapidly". wn