Omega

Boyd’s Bible Dictionary:

(great or long O). Last letter of Greek alphabet (Rev. 1:8).

Concise Bible Dictionary:

Ω ω
The last letter of the Greek alphabet: with Alpha, the first letter, it is descriptive of Jehovah as the beginning and the ending of all purpose concerning man (Rev. 1:8,11; Rev. 21:6; Rev. 22:13).

Strong’s Dictionary of Greek Words:

Greek:
Ω
Transliteration:
omega
Phonic:
o’-meg-ah
Meaning:
the last letter of the Greek alphabet, i.e. (figuratively) the finality
KJV Usage:
Omega

Jackson’s Dictionary of Scripture Proper Names:

finality last letter of Greek alphabet

Potts’ Bible Proper Names:

The last; the end; the last letter of the Greek alphabet, Rev. 1:8. {Extremus; finis}