ο
ο
Ο, ο, ὂ μικρόν, little or short o, as opp. to ὂ μέγα great or long o, i. e. double o (for ω was orig. written , i. e. oo) : fifteenth letter in the Greek alphabet: as numeral οʹ 70, but ͵ο 70,000. In early times ο represents both ο and ω; and in many words must have sounded like ου, as in βόλομαι for βούλομαι; while reversely, in Ionic μοῦνος νοῦσος κοῦρος οὔνομα stand for μόνος νόσος κόρος ὄνομα. Dialect. changes: Aeolic for α, as στροτός for στρατός;— for ε, Ἐρχόμενος for Ὀρχόμενος (Boeot.);—for υ, as ὄνυμα στύμα for ὄνομα στόμα.
Doric often into οι, ἀγνοιέω πτοιέω πνοιά for ἀγνοέω ἀλοάω πτοέω.
like α, ο is often rejected or prefixed for euphony, as κέλλω ὀκέλλω, δύρομαι ὀδύρομαι.
in compd. Adjectives, ο is changed metri grat. into η, θεογενής ξιφοφόρος into θεηγενής ξιφηφόρος.