adjective.
Useful as a means or an instrument; serving to promote an end.
The Century Dictionary and Cyclopedia
Useful as an instrument or means to promote an end or purpose; serviceable; being of service.
Acting as a subordinate instrument; fitted or disposed to serve in an inferior capacity; subordinate; hence, of persons and conduct, truckling; obsequious.
the GNU version of the Collaborative International Dictionary of English
adjective.
Fitted or disposed to subserve; useful in an inferior capacity; serving to promote some end; subordinate; hence, servile, truckling.