adelpho-, adelph-, -adelphia, -adelphous +
2. An ancient city of Asia Minor northeast of the Dead Sea in modern-day Jordan. The chief city of the Ammonites, it was enlarged and embellished by Ptolemy II Philadelphus (285-246 B.C.) and named in honor of him. Amman, the capital of Jordan, is now on the site.
3. The largest city of Pennsylvania, in the southeast part of the state on the Delaware River.
It was founded as a Quaker colony by William Penn in 1681 on the site of an earlier Swedish settlement.
The First and Second Continental Congresses (1774 and 1775-1776) and the Constitutional Convention (1787) met in the city, which served as the capital of the United States from 1790 to 1800.