Phil ‧ a ‧ del ‧ phi ‧ a /ˌfɪləˈdelfiə◂/ BrE AmE
a city in the US state of Pennsylvania, which is an important port and an industrial and financial centre. Philadelphia, which is informally called Philly, is the fifth largest city in the US. The Declaration of Independence from Britain was signed in Philadelphia in 1776, and the city was the first capital of the new United States.