definition of
[Mercury]

[1] #1 Mercury n. [mercury, 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. (Roman mythology) messenger of Jupiter and god of commerce; counterpart of Greek Hermes. wn

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

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