mercury

mercury [mʉr′kyoor ē, mʉr′kyərē]

n.

[L Mercurius, Mercury, of Etr orig.]

1. [M-] Rom. Myth. the messenger of the gods, god of commerce, manual skill, eloquence, cleverness, travel, and thievery: identified with the Greek Hermes

2. [M-] the eighth largest planet in the solar system and the one nearest to the sun: diameter, c. 4,880 km ( c. 3,030 mi); period of revolution, 87.97 earth days; period of rotation, 58.65 earth days; symbol, ☿ 3,030 mi); period of revolution, 87.97 earth days; period of rotation, 58.65 earth days; symbol, ☿

3. [ME < ML mercurius < L, Mercurius, Mercury: so named by the alchemists because of its fluidity: see QUICKSILVER]

a) a heavy, silver-white metallic chemical element, liquid at ordinary temperatures, which sometimes occurs in a free state but usually in combination with sulfur; quicksilver: it is used in thermometers, air pumps, electrical products, etc. and in dentistry: symbol, Hg; at. no., 80: see the periodic table of elements in the Reference Supplement

b) the mercury column in a thermometer or barometer

4. pl. Mercuries Now Rare a messenger or guide

5. Bot.

a) any of a genus (Mercurialis) of plants of the spurge family

b) an edible European plant (Chenopodium bonus-henricus) of the goosefoot family