Ω
1. Ω, ω, ὦ μέγα, twenty-fourth letter of the Gr. alphabet: —as a numeral ω41 = 800, but 'ω = 800, 000. The name of ὦ μέγα, "great or long" ο, was given at a later period to distinguish it from ὂ μικρόν "little or short" ο: but the form Ω was not adopted at Athens till the Archonship of Euclides (B. C. 403); v. sub E, H. Changes of ω, esp. in the dialects:
1. ionic sometimes for α, as ὤνθρωπος ὤριστος for ἄνθρωπος ἄριστος.
2. ionic also for αυ, as θῶμα τρῶμα for θαῦμα τραῦμα:—this is also doric, ὦλαξ for αὖλαξ.
3. aeolic and doric ω for ου, as ὠρανός Μῶσα κῶρος λιπῶσα for οὐρανός Μοῦσα κοῦρος λιποῦσα; so, ου and ους in gen. sg. and acc. pl. of 2nd decl. pass into ω and ως.
4. doric, ω becomes α_, as πρῶτος πρώτιστος θεωρός become πρᾶτος πράτιστος θεα_ρός; so gen. pl. of 1st dec. -ῶν becomes -ᾶν.
5. Aeol. sometimes also υ, as χελύνη for χελώνη.