the cat's whiskers

the cat's whiskers

or

the cat's pyjamas

BRITISH, OLD-FASHIONED
If you describe someone or something as the cat's whiskers or the cat's pyjamas, you mean they are the best person or thing of their kind. She had this great dress on with huge skirts, and she thought she was the cat's whiskers as she walked into the room. We critics variously declared the show brilliant, the cat's pyjamas, breathtaking, and unmissable. Note: These expressions were originally American and became popular in Britain during the 1920s. `Cat's whisker' was also the name of a fine wire in a crystal wireless receiver.
See also: whisker

the cat's whiskers

an excellent person or thing. informal
Other similar phrases include the cat's pyjamas and the chiefly North American the cat's miaou .
See also: whisker

the cat’s ˈwhiskers/pyˈjamas

(informal, often ironic) the best person, idea, thing, etc: She thinks she’s the cat’s whiskers.
See also: pyjama, whisker