Which of the following is NOT a type of shirt?

The correct answer is the overcoat. An overcoat is not a type of shirt; rather, it is an outerwear garment typically worn over other clothing for warmth and protection. It is designed to be worn outside and can vary in length, style, and material, but it does not serve the same function as a shirt.

In contrast, a tuxedo, polo, and henley are all types of shirts that vary in design and purpose. A tuxedo shirt is often worn with formal wear and comes with specific features such as pleats or a winged collar. A polo shirt is a casual style with a collar and a placket, typically made from cotton or a cotton blend, and features short sleeves. A henley is a collarless pullover shirt with a buttoned placket and can be short or long-sleeved, often made from thicker fabrics.

Thus, the overcoat is distinctly different in context and use from the other options, confirming that it does not fit the category of shirt.