Source : Webster's Revised Unabridged Dictionary (1913)

Fifth \Fifth\, a. [OE. fifte, fifthe, AS. f[=i]fta. See {Five}.]
   1. Next in order after the fourth; -- the ordinal of five.

   2. Consisting of one of five equal divisions of a thing.

   {Fifth monarchy men} (Hist.), a fanatical sect in England, of
      the time of the commonwealth, who maintained that there
      would be a fifth universal monarchy, during which Christ
      would reign on earth a thousand years.

   {Fifth wheel}, a horizontal wheel or segment above the fore
      axle of a carriage and beneath the body, forming an
      extended support to prevent careening.