sub·ser·vi·ent 
(səb-sûrvē-ənt)
(səb-sûrvē-ənt)adj.
1. Subordinate in capacity or function.
2. Obsequious; servile.
3. Useful as a means or an instrument; serving to promote an end.
[Latin subserviēns, subservient-, present participle of subservīre, to subserve; see SUBSERVE.]
sub·servi·ence, sub·servi·en·cy n.
sub·servi·ent·ly adv.