subserve

verb3

1. •
   To serve to promote (an end); to be useful to.

   • Their principles will cease to be dear to them, whenever they shall cease to subserve the purposes of good order. — 1840
2. •
   To assist in carrying out.

   • 'Tis a greater credit to know the ways of captivating Nature, and making her subserve our purposes, than to have learnt all the intrigues of policy. — 1665
3. •
   To be subservient to.

   • Ah, if only he had asked her to subserve him, to be his slave! — 1921