AO DAI Meaning of AO DAI in English [ 'aʊ ˌdʌɪ ]■ noun ( plural ~s ) a Vietnamese woman's traditional long-sleeved tunic with ankle-length panels at front and back, worn over trousers.Origin1960s: Vietnamese. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004