Source : Webster's Revised Unabridged Dictionary (1913)

Quicksilver \Quick"sil`ver\, n. [Quick living + silver; -- so
   called from its fluidity; cf. G. quecksilber, L. argentum
   vivum. See {Quick}, a.] (Chem.)
   The metal mercury; -- so called from its resemblance to
   liquid silver.

   {Quicksilver horizon}, a mercurial artificial horizon. See
      under {Horizon}.

   {Quicksilver water}, a solution of mercury nitrate used in
      artificial silvering; quick water.

Source : WordNet®

quicksilver
     adj : 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" [syn: {erratic}, {fickle}, {mercurial},
            {quicksilver(a)}]
     n : a heavy silvery toxic univalent and bivalent metallic
         element; the only metal that is liquid at ordinary
         temperatures [syn: {mercury}, {hydrargyrum}, {Hg}, {atomic
         number 80}]

Source : Free On-Line Dictionary of Computing

Quicksilver
     
         A {dBASE}-like compiler for {MS-DOS} from
        {WordTech}.
     
        (1995-05-11)