Source : Webster's Revised Unabridged Dictionary (1913)

Jointly \Joint"ly\, adv.
   In a joint manner; together; unitedly; in concert; not
   separately.

         Then jointly to the ground their knees they bow.
                                                  --Shak.

Source : WordNet®

jointly
     adv 1: in collaboration or cooperation; "this paper was written
            jointly"
     2: in conjunction with; combined; "Our salaries put together
        couldn't pay for the damage"; "we couldn`t pay for the
        damages with all out salaries put together" [syn: {collectively},
         {conjointly}, {together}, {put together}]