42 Pa. C.S. § 1501
The following words and phrases when used in this subchapter shall have, unless the context clearly indicates otherwise, the meanings given to them in this section:
"Court." The Supreme Court or the court of common pleas of each judicial district under the direction of the Supreme Court.
"Political subdivision." Any municipality except the City and County of Philadelphia.
"Population." The number of persons residing within a political subdivision or part thereof as determined by the then current Federal decennial or Federal special census.
"Population density." The number of persons residing within a political subdivision or part thereof as determined by dividing such number by the land area expressed in square miles as determined in the official publication of the Bureau of Statistics of the Department of Commerce.
42 Pa.C.S. § 1501