subservient -- (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)
implemental, instrumental, subservient -- (serving or acting as a means or aid; "instrumental in solving the crime")
slavish, subservient, submissive -- (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")