The Collaborative International Dictionary of English v.0.48:

Belfast \Belfast\ n.
   the capital of Northern Ireland; -- the center of Irish
   Protestantism.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

Belfast
    n 1: capital and largest city of Northern Ireland; the center of
         Protestantism in Northern Ireland [syn: Belfast, capital
         of Northern Ireland]

U.S. Gazetteer Places (2000):

Belfast, PA -- U.S. Census Designated Place in Pennsylvania
   Population (2000):    1301
   Housing Units (2000): 517
   Land area (2000):     1.101642 sq. miles (2.853239 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    1.101642 sq. miles (2.853239 sq. km)
   FIPS code:            05152
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             40.783213 N, 75.276481 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Belfast, PA
    Belfast


U.S. Gazetteer Places (2000):

Belfast, ME -- U.S. city in Maine
   Population (2000):    6381
   Housing Units (2000): 3121
   Land area (2000):     34.038982 sq. miles (88.160555 sq. km)
   Water area (2000):    4.315295 sq. miles (11.176562 sq. km)
   Total area (2000):    38.354277 sq. miles (99.337117 sq. km)
   FIPS code:            03950
   Located within:       Maine (ME), FIPS 23
   Location:             44.425896 N, 69.011646 W
   ZIP Codes (1990):     04915
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Belfast, ME
    Belfast