FROM http://vines.mike-obrien.net/
Fornication, Fornicator
1 porneia (Noun)
Is used (a) of "illicit sexual intercourse," in Joh. 8:41; Ac. 15:20,29; 21:25; 1Co. 5:1; 6:13,18; 2Co. 12:21; Ga. 5:19; Eph. 5:3; Col. 3:5; 1Th. 4:3; Re. 2:21; 9:21; in the plural in 1Co. 7:2; in Mt. 5:32; 19:9 it stands for, or includes, adultery; it is distinguished from it in 15:19; Mr. 7:21; (b) metaphorically, of "the association of pagan idolatry with doctrines of, and professed adherence to, the Christian faith," Re. 14:8; 17:2,4; 18:3; 19:2; some suggest this as the sense in Re. 2:21.
2 pornos (Noun)
Denotes "a man who indulges in fornication, a fornicator," 1Co. 5:9,10,11; 6:9; Eph. 5:5, RV; 1Ti. 1:10, RV; Heb. 12:16; 13:4, RV; Re. 21:8; 22:15, RV (AV, "whoremonger").
3 porneuo (Verb)
to commit fornication," is used (a) literally, Mr. 10:19; 1Co. 6:18; 10:8; Re. 2:14,20, see (a) and (b) above; (b) metaphorically, Re. 17:2; 18:3,9.
4 ekporneuo (Verb)
A strengthened form of No. 1 (ek, used intensively), "to give oneself up to fornication," implying excessive indulgence, Jude. 1:7.