The ao dai (Vietnamese: áo dài) is a Vietnamese national costume, now most commonly for women. In its current form, it is a tight-fitting silk tunic worn over pantaloons. The word is pronounced ǎːwzːj. Áo is derived from a Middle Chinese word meaning 'padded coat' (襖). Dài means 'long'. The word 'ao dai' was originally applied to the outfit worn at the court of the Nguyễn Lords at Huế in the 18th century. This outfit evolved into the áo ngũ thn, a five-paneled aristocratic gown worn in the 19th and early 20th centuries. On Tết and other occasions, Vietnamese men may wear an áo gấm (brocade robe), a version of the ao dai made of thicker fabric.