Source : Webster's Revised Unabridged Dictionary (1913)

Whig \Whig\, n. [See {Whey}.]
   Acidulated whey, sometimes mixed with buttermilk and sweet
   herbs, used as a cooling beverage. [Obs. or Prov. Eng.]

Whig \Whig\, n. [Said to be from whiggam, a term used in
   Scotland in driving horses, whiggamore one who drives horses
   (a term applied to some western Scotchmen), contracted to
   whig. In 1648, a party of these people marched to Edinburgh
   to oppose the king and the duke of Hamilton (the Whiggamore
   raid), and hence the name of Whig was given to the party
   opposed to the court. Cf. Scot. whig to go quickly.]
   1. (Eng. Politics) One of a political party which grew up in
      England in the seventeenth century, in the reigns of
      Charles I. and II., when great contests existed respecting
      the royal prerogatives and the rights of the people. Those
      who supported the king in his high claims were called
      Tories, and the advocates of popular rights, of
      parliamentary power over the crown, and of toleration to
      Dissenters, were, after 1679, called Whigs. The terms
      Liberal and Radical have now generally superseded Whig in
      English politics. See the note under {Tory}.

   2. (Amer. Hist.)
      (a) A friend and supporter of the American Revolution; --
          opposed to {Tory}, and {Royalist}.
      (b) One of the political party in the United States from
          about 1829 to 1856, opposed in politics to the
          Democratic party.

Whig \Whig\, a.
   Of or pertaining to the Whigs.

Source : WordNet®

Whig
     n 1: urged social reform in 19th century England
     2: a supporter of the American Revolution
     3: a member of the Whig Party in the United States in
        pre-Civil-War times