serve a, his, its, etc. purpose

serve (one's) purpose

To fit or satisfy someone's requirements; to be useful for or fit to achieve someone's aim, goal, or purpose. Well, it isn't a very pretty car, but it should serve our purpose just fine. Child: "But mom, I want a smartphone!" Mother: "Nonsense, the cell phone you already have serves your purpose just fine."
See also: purpose, serve
Farlex Dictionary of Idioms.

serve a, his, its, etc. ˈpurpose

,

serve the ˈpurpose (of doing something)

(British English also serve his, its, etc. ˈturn) be useful for a particular purpose or period of time; be good or useful enough for somebody: It’s not a very good radio, but it serves its purpose. He used his friends and then abandoned them when they had served their turn.
See also: purpose, serve
Farlex Partner Idioms Dictionary
See also:
  • serve (one's) purpose
  • serve the purpose
  • serve a purpose
  • fit in with (someone or something)
  • You cannot get a quart into a pint pot
  • you can't get a quart into a pint pot
  • fit the bill
  • give (someone) a fit
  • give someone a fit
  • fiddle