The term 'bee's knees' is an idiom that originated in the 1920s and is used to describe something that is excellent or outstanding. It is derived from the phrase 'the bee's knees, ' which was a slang term for something small and insignificant. The crossword solutions for the term 'bee's knees' are 'BEST, ' 'TOPS, ' 'PRIME, ' and 'ACE.' These words all refer to something that is of the highest quality or the BEST of its kind.