the last letter of the Greek alphabet, i.e. (figuratively) the finality
KJV Usage: Omega.
TBESG:
Ὦ
Omega
G:N
Ω, ω, ὦ μέγα (cf. ὂ μικρόν), omega, ô, the twenty-fourth and last letter. As a numeral, ω᾽ = 800, ω, = 800,000. As a symbol of the last (= τὸ τέλος), τὸ Ὦ (Rec. Ω, L, ὦ, T, ω), the Omega: Refs Rev.1:8 21:6 22:13 (cf. Ἄλφα).† (AS)
Thayer:
1) the last letter in the Greek alphabet 2) the last
Ω
Ō
o'-meg-ah
The last letter of the Greek alphabet, that is, (figuratively) the finality