Source : Webster's Revised Unabridged Dictionary (1913)

Bond servant \Bond" serv`ant\
   A slave; one who is bound to service without wages.

         If thy brother . . . be waxen poor, and be sold unto
         thee; thou shalt not compel him to serve as a bond
         servant: but as an hired servant.        --Lev. xxv.
                                                  39, 40.

Source : WordNet®

bond servant
     n : someone bound to labor without wages