What does Vietnamese Ao Dai mean?

The national costume of Vietnam. "Ao Dai" is a unique Vietnamese women's traditional dress, often cut with silk-like texture of light and soft fabrics, style similar to the Chinese cheongsam, high neck, narrow sleeves, the upper part of the body, the two sides from the waist that is slit, the hemline stretch, with the same flowery or white fabric, loose pants, no matter squatting, sitting, riding a bike is very convenient, and has now become the national costume of Vietnam. The Vietnamese government encourages women to wear the national dress on official occasions, and also stipulates that secondary schools should take Vietnamese traditional dress as school uniforms. Vietnamese traditional men's clothing is similar to the Chinese long shirt, and now men wear suits.