ΟΟ ο, sixteenth (later fifteenth) letter in Gr. alphabet: as numeral ό = 70, but o = 70,000. The name of the letter was οὖ,Pl.Cra. 414c, al., Callias ap.Ath.10.453d, Neoptol. ap. eund.10.454f,AP9.385 (Steph. Gramm.): this name was in Plato's time pronounced like the letter itself, Pl.Cra.393d; ο scanned long, Achae.33.4; τὸ ο̄ (v.l. ου) στοιχεῖονSuid. s.v. Φιλοξένου γραμμάτιον; later called ὂ μικρόν (Hdn.Epim.209, Theognost.Can.13),