From Ancient Greek ο (o). Introduced at the end of the 11th century to replace the diphthong աւ (aw), which by then had begun to be pronounced as IPA(key): [o], e.g. աւգոստոս (awgostos) became օգոստոս (ōgostos).
օ lowercase (uppercase Օ)
- The 38th letter of Armenian alphabet. Represents close-mid back rounded vowel: IPA(key): [o]. Transliterated as ō (Hübschmann-Meillet-Benveniste) or ò (ISO 9985).
- The letter ո (o) too is pronounced as IPA(key): [o], except word-initially.
- Because this letter is a late addition, it has no numerical value.
- In Traditional Armenian orthography this is the 37th letter.