Unknown. One of many such informal phrases coined in the early 20th century for no apparent reason, of which only a few have endured. One possible origin is from the British expression "B's and E's" meaning "be all and end all". Another is a playful mispronunciation of business.
the bee's knees
- (idiomatic, dated) Something excellent, outstanding.
- We had strawberry shortcake for breakfast on Saturday and the kids thought it was the bee’s knees.
something excellent, outstanding
- Dutch: jé van hét (nl)
- French: c'est le must (fr) (colloquial), le nec plus ultra (fr) (standard)
- Spanish: la mamá de Tarzán (es) (referring to people, Hispano America), lo más (es), la hostia (es) (colloquial, Spain), la leche (es) (colloquial, Spain), la polla (es) (vulgar, Spain), la repera (es) (colloquial, Spain), la neta (es) (colloquial, Mexico), las perlas de la virgen (es) (colloquial, Mexico)