This expression sounds extremely strange to anyone who is not familiar with it as of course cats do not wear pyjamas. If you want to know what this expression is used for and why then keep reading!
This English expression is used in order to express that something is great. Like many other English idioms it involves an animal although it is not used exclusively in relation to cats.
This expression was first used in the 1920s in the United States as slang. It came into usage at the same time as other similar expressions such as “the bee’s knees” and “the cat’s whiskers.” The word “cat” does not refer to the animal but in fact to the fact that the word “cat” was used to describe female jazz artists at the time. This was combined with the word “pyjamas” which were, at the time, a relatively new invention in order to describe something which was extremely desirable.
The expression can be found with the word “pyjamas” spelt in the British English way or as “pajamas” following the conventions of American English.
An example of the expression can be found in a quote by the American actor George Dzundza. It reads “I love Philadelphia. I was shocked at what a great city this is. For me, it is the cat’s pajamas. I love everything about it. I love where I live. I love the people. I have been met with such kindness and affection here.”