The Collaborative International Dictionary of English v.0.48:

Subservient \Sub*serv"i*ent\, a. [L. subserviens, -entis, p. pr.
   See Subserve.]
   Fitted or disposed to subserve; useful in an inferior
   capacity; serving to promote some end; subordinate; hence,
   servile, truckling.
   [1913 Webster]

         Scarce ever reading anything which he did not make
         subservient in one kind or other.        --Bp. Fell.
   [1913 Webster]

         These ranks of creatures are subservient one to
         another.                                 --Ray.
   [1913 Webster]

         Their temporal ambition was wholly subservient to their
         proselytizing spirit.                    --Burke.
   [1913 Webster]

WordNet (r) 3.0 (2006):

subservient
    adj 1: compliant and obedient to authority; "editors and
           journalists who express opinions in print that are
           opposed to the interests of the rich are dismissed and
           replaced by subservient ones"-G. B. Shaw
    2: serving or acting as a means or aid; "instrumental in solving
       the crime" [syn: implemental, instrumental,
       subservient]
    3: abjectly submissive; characteristic of a slave or servant;
       "slavish devotion to her job ruled her life"; "a slavish yes-
       man to the party bosses"- S.H.Adams; "she has become
       submissive and subservient" [syn: slavish, subservient,
       submissive]