Philadelphia = "brotherly love"
1) a city of Lydia in Asia Minor, situated near the eastern base of of Mount Tmolus, founded and named by the Pergamene king, Attalus II Philadelphus. After the death of Attalus III Philometor, 133 BC, it together with his entire kingdom came by his will under the jurisdiction of the Romans.
Part of Speech: noun proper locative
Citing in TDNT: 1:144,*
From Φιλάδέλφος Philadelphos (the same as G5361), a king of Pergamos; Philadelphia, a place in Asia Minor: - Philadelphia.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root Φιλαδέλφεια; click on the second column to search for that grammatical form of the root Φιλαδέλφεια; click on the third column to search for that word and grammatical form; click on the total to search for the root Φιλαδέλφεια.