Ρ ρ, ῥῶ , τό, indecl., twentieth (later seventeenth) letter of the Gr. alphabet: as numeral ρ́ = 100, but ρ᾽ = 100,000: reckoned as a semivowel by Arist.Po.1456b28: the name ῥῶ occurs in Ar.Th. 781, Callias ap.Ath.10.453d, Pl.Cra.426c, BCH29.483 (Delos), etc.