Source : Webster's Revised Unabridged Dictionary (1913)

Ulster \Ul"ster\, n.
   A long, loose overcoat, worn by men and women, originally
   made of frieze from Ulster, Ireland.

Source : WordNet®

Ulster
     n 1: a historic division of Ireland located in the northeastern
          part of the island; six of Ulster's nine counties are in
          Northern Ireland
     2: loose long overcoat of heavy fabric; usually belted