Topic summary
Omega
Omega (US: , UK: ; uppercase Ω, lowercase ω) is the twenty-fourth and last letter of the Greek alphabet. In the Greek numeric system/isopsephy (gematria), it has a value of 800. The name of the letter was originally ὦ (ō̂), but it was later changed to (ō̂ méga 'big o') in the Middle Ages to distinguish it from omicron⟨ο⟩, whose name means 'small o', as both letters had come to be pronounced . In modern Greek, its name has fused into ωμέγα (oméga).
In phonetic terms, the Ancient Greek Ω represented a longopen-mid back rounded vowel, in contrast to omicron, which represented the close-mid back rounded vowel, and the digraph⟨ου⟩, which represented the longclose back rounded vowel. In modern Greek, both omega and omicron represent the mid back rounded vowel. The letter omega is transliterated into a Latin-script alphabet as ō or o.
As the final letter in the Greek alphabet, omega is often used to denote the last, the end, or the ultimate limit of a set, in contrast to alpha, the first letter of the Greek alphabet, as in the phrase Alpha and Omega.