The term 'CAT's pajamas' is an old-fashioned slang phrase used to describe something that is excellent or fashionable. The crossword solutions for this term are FUR (3 letters) and BEESKNEES (9 letters). FUR is a type of material made from the coats of animals, such as cats, which could be used to make pajamas. BEESKNEES is another slang phrase meaning something that is excellent or fashionable, which could also be used to describe CAT's pajamas.