The term 'COLLAR OR JACKET' can be summarized by the crossword solution 'ETON'. Eton is a type of formal clothing, typically worn by men, which consists of a long-sleeved shirt with a high collar and a waistcoat or jacket. It is usually made from lightweight fabrics such as cotton or linen and is often worn with a tie. The style originated in England in the 19th century and is still popular today.