Omega is defined as the last of something, particularly the last letter in the Greek alphabet.
(noun)An example of the omega is the final day on earth.
See omega in Webster's New World College Dictionary
noun
Origin: Gr ō + mega, great (see mega-): lit., great (i.e., long) o, to distinguish from o mikron: see omicron
See omega in American Heritage Dictionary 4
noun
Origin:
Origin: Middle English
Origin: , from Greek ō mega, large o (from its being a long vowel in Greek)
Origin: : ō, the letter o
Origin: + mega
Origin: , neuter of megas, large, great; see meg- in Indo-European roots
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