The Vietnamese word "sơ mi" is a noun that means "shirt." Specifically, it refers to a type of shirt that is typically buttoned down the front and often has a collar. "Sơ mi" shirts are commonly worn for formal occasions, work, or casual outings, making them a versatile item in many people's wardrobes.
While "sơ mi" primarily refers to a button-up shirt, in some contexts, it can also refer to a less formal or casual shirt, depending on the style and fabric.