The term 'summer hat' can be broken down into two crossword solutions: PANAMA (6 letters) and BOATER (6 letters). A PANAMA hat is a traditional brimmed straw hat originating from Ecuador and made of the plaited leaves of the toquilla palm. It is often associated with summer fashion and is popular in tropical climates. A BOATER is a type of summer hat with a flat top and brim, typically made of straw or felt. It is often worn with a blazer or suit and is associated with nautical fashion.