The term 'SUMMER SHIRT' can be broken down into two crossword solutions: TEE (3 letters) and TANKTOP (7 letters). A TEE is a type of shirt that has short sleeves and a round neckline. It is usually made of cotton or a cotton blend and is a popular choice for casual wear. A tanktop is a sleeveless shirt with a low neckline and thin straps. It is often made of lightweight fabrics such as cotton or polyester and is a popular choice for warm weather.