Bee’s knees

If someone or something is the 'bee’s knees',' the 'cat's whiskers' or the 'cat's pyjamas' then that person or thing is the pinnacle of excellence or quality. Although many explanations of the origin of these have been put forward, they all remain exercises in imagination rather than etymology. 'Bee’s knees' and 'cat’s whiskers' have survived largely in Britain, while 'cat's pyjamas' is more popular in America. These are among the few that seem to have survived from what was once a fashionable trend to use nonsensical or meaningless phrases to denote excellence during the 1920s in America. They then made their way across the Atlantic to Britain and spread to other parts of the English-speaking world. Other now defunct phrases from this trend, attributing fictitious or jocular properties to animals or insects, were 'gnat’s elbows', 'snake’s hips', 'eel’s ankles', 'oyster’s earrings', 'canary’s tusks', 'elephant’s adenoids' etc. This unique American trend generated an almost endless list of such phrases ad nauseam. Mercifully, the trend did not last long. Inexplicably, only 'bee’s knees', 'cat’s whiskers', and cat's pyjamas' appear to have survived.