WordNet (r) 3.0 (2006):

Pittsburgh
    n 1: a city in southwestern Pennsylvania where the confluence of
         the Allegheny River and Monongahela River forms the Ohio
         River; long an important urban industrial area; site of
         Carnegie Mellon University and the University of Pittsburgh

U.S. Gazetteer Places (2000):

Pittsburgh, PA -- U.S. city in Pennsylvania
   Population (2000):    334563
   Housing Units (2000): 163366
   Land area (2000):     55.584434 sq. miles (143.963017 sq. km)
   Water area (2000):    2.767416 sq. miles (7.167573 sq. km)
   Total area (2000):    58.351850 sq. miles (151.130590 sq. km)
   FIPS code:            61000
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             40.441419 N, 79.977292 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Pittsburgh, PA
    Pittsburgh