What does bee's knees mean?

bee's knees meaning in Etymology Dictionary

1923, a survivor of a craze surrounding this 12 months for slang terms denoting "excellence" and based on pet structure. Also existed into the more ribald kind bee's nuts. Various other versions that lasted through the century are cat's whiskers (1923), cat's sleepwear, cat's meow. More obscure instances tend to be canary's tusks, pet's nuts and flea's eyebrows. The trend nonetheless had a heartbeat in Britain at the conclusion of the century, as attested because of the appearance of puppy's bollocks in 1989. Bee's knee ended up being made use of dating back 1797 for "anything insignificant."