Source : Webster's Revised Unabridged Dictionary (1913)

Orangeman \Or"ange*man\, n.; pl. {-men}.
   One of a secret society, organized in the north of Ireland in
   1795, the professed objects of which are the defense of the
   regning sovereign of Great Britain, the support of the
   Protestant religion, the maintenance of the laws of the
   kingdom, etc.; -- so called in honor of William, Prince of
   Orange, who became William III. of England.

Source : WordNet®

Orangeman
     n : a member of a society founded in Ireland in 1795 to uphold
         Protestantism and the British sovereign