YΦXΨΩ were the letters added by the ancient greeks to the early northsemitic (phoenician) alphabet.

---

SHAPE: Very few cities of the Western-Eastern greek alphabet groups used omega: usually it was a variation of the O omikron. Either with a dot in the middle of it, or with a gap at its bottom.
Omega transformations:

---

SOUND: Just like the pair E [e] and H [ε:] covered both short and long /e/, the greeks wished to give a 'brother' to O [o] as its long /o/ twin. They created Ω for [o:]. This pronunciation lasted till hellenistic times. Afterwards, (till today) they were both pronounced [o].
It should be noted the oooold pronunciation of omega as close to [u] survives even today in some words:
anc.gre: σάπων [`sapo:n] = eng:soap mod.gre: σαπoύνι [sa`puni]
In some villages, peasants pronounce the omega distinctly:
e.g. the 'correct' pronunciation for gre: πάνω = eng:up is [`pano], but they pronounce it [`panu]... as it might be pronounced some millennia ago.

---

NAME: ETYMOLOGY/SPELLING: (in polytonic script) Ancient name: «» . In the middle times the two /o/s were distinguished as
«    μέγα» [o] [ `meγa] = O great, big to contrast it to «    μικρόν» [o] [mi`kron] = O small.
Hence the name: «μέγα» [o`meγa] and [`omikron].

---

COMBINATIONS: Check the long diphthong ΩI and mediaeval ΩI .

---

MORE GREEK WORDS STARTING WITH OMEGA
•polytonic ὥρα = monotonic ώρα = eng:hour = fre:heur