Hierapolis = "holy city"
1) a city of Phrygia, situated above the junction of the rivers Lycus and Maeander, near Colosse and Laodicea
Part of Speech: noun proper locative
From G2413 and G4172; holy city; Hierapolis, a place in Asia Minor: - Hierapolis.
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 Ἱεράπολις; click on the second column to search for that grammatical form of the root Ἱεράπολις; click on the third column to search for that word and grammatical form; click on the total to search for the root Ἱεράπολις.