1. (noun)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
2. (adj)erratic, fickle, mercurial, quicksilver(a) liable to sudden unpredictable change "erratic behavior"; "fickle weather"; "mercurial twists of temperament"; "a quicksilver character, cool and willful at one moment, utterly fragile the next"
Definition of 'quicksilver'
