The Collaborative International Dictionary of English v.0.48:
bond-servant \bond-servant\, Bond servant \Bond"
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.
WordNet (r) 3.0 (2006):
n 1: someone bound to labor without wages