Source : Webster's Revised Unabridged Dictionary (1913)

Bo \Bo\, interj. [Cf. W. bw, an interj. of threatening or
   frightening; n., terror, fear, dread.]
   An exclamation used to startle or frighten. [Spelt also {boh}
   and {boo}.]

Source : Free On-Line Dictionary of Computing

bo
     
         The {country code} for Bolivia.
     
        (1999-01-27)