The Collaborative International Dictionary of English v.0.48:

Jo \Jo\, n.; pl. Joes. [Etymol. uncertain.]
   A sweetheart; a darling. [Scot.] --Burns.
   [1913 Webster]

The Free On-line Dictionary of Computing (30 December 2018):

jo

    The country code for Jordan.

   (1999-01-27)