1) illicit sexual intercourse
1a) adultery, fornication, homosexuality, lesbianism, intercourse with animals etc.
1b) sexual intercourse with close relatives; Lev. 18
1c) sexual intercourse with a divorced man or woman; Mar 10:11,Mar 10:12
2) metaphorically the worship of idols
2a) of the defilement of idolatry, as incurred by eating the sacrifices offered to idols
Part of Speech: noun feminine
Citing in TDNT: 6:579, 918
From G4203; harlotry (including adultery and incest); figuratively idolatry: - fornication.
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 πορνεία; click on the second column to search for that grammatical form of the root πορνεία; click on the third column to search for that word and grammatical form; click on the total to search for the root πορνεία.