ao dai 
(ou dī, ô)
(ou dī, ô)n. pl. ao dais
A long-sleeved, usually full-length garment with sides slit up to the hips, traditionally worn by Vietnamese women over loose trousers.
[Vietnamese áo dài : áo, tunic (from Middle Chinese ʔaw´, padded coat; also the source of Mandarin ǎo) + dài, long.]