A.T. Robertson Commentary Jude 1:6

"And angels that kept not their own principality, but left their proper habitation, he hath kept in everlasting bonds under darkness unto the judgment of the great day." — Jude 1:6 (ASV)

And angels (αγγελους δε). The second example in Jude, the fallen angels, accusative case after τετηρηκεν (perfect active indicative of τηρεω, for which verb see 2 Peter 2:4,7) at the end of the verse (two emphatic positions, beginning and end of the clause).

Kept not (μη τηρησαντας). First aorist active participle with negative μη, with play on "kept not" and "he hath kept."

Principality (αρχην). Literally, "beginning," "rule," (first place of power as in 1 Corinthians 15:24; Romans 8:38). In Ac 10:11 it is used for "corners" (beginnings) of the sheet. In Eph 6:12 the word is used for evil angels. See De 32:8. Both Enoch and Philo (and Milton) discuss the fallen angels.

But left (αλλα απολιποντας). Second aorist active participle of απολειπω, old verb, to leave behind (2 Timothy 4:13,20).

Their own proper habitation (το ιδιον οικητηριον). Old word for dwelling-place (from οικητηρ, dweller at home, from οικος), in N.T. only here and 2 Corinthians 5:2 (the body as the abode of the spirit).

In everlasting bonds (δεσμοις αιδιοις). Either locative (in) or instrumental (by, with). Αιδιος (from αε, always), old adjective, in N.T. only here and Ro 1:20 (of God's power and deity). It is synonymous with αιωνιος (Matthew 25:46). Mayor terms αιδιος an Aristotelian word, while αιωνιος is Platonic.

Under darkness (υπο ζοφον). See 2 Peter 2:4 for ζοφος. In Wisd. 17:2 we find δεσμιο σκοτους (prisoners of darkness).

Great (μεγαλης). Not in 2 Peter 2:9, which see for discussion.