rein in

verb

1. To stop or slow a horse by pulling the reins
2. To stop or slow something, by exercising control.

   “The government has no other option than to rein in public spending.”

   ““As you are well aware, over the last few months we’ve made a considerable effort to rein in costs, but it simply hasn’t been enough,” Daniel Ek, Spotify’s chief executive, said in a note to employees on Monday.”