Jude 1:6,7

Principality. That is, the state in which they were first created, their original dignity. (Challoner) --- Having given themselves over to [7] fornication, or to excessive uncleanness. --- Going after other flesh, and seeking unnatural lusts, with those of the same sex. (Witham) --- Impurity punished by fire and sulphur. Fire is a punishment proportioned to the criminal passion of the voluptuous. That of Sodom was most dreadful, but then it was of short duration. There is another fire that will never be extinguished.

[BIBLIOGRAPHY]

Given themselves over to fornication, exfornicatæ, Greek: ekporneusasai, excessive fornications, the signification being stronger, and increased by Greek: ek.