putting the brakes on

Verb

put the brakes on (third-person singular simple present puts the brakes on, present participle putting the brakes on, simple past and past participle put the brakes on)

1. (idiomatic, transitive) To stop (an event, action, or process) or to slow it down.
   • "[T]he fight I saw that day made the others look like a young ladies' quadrille. . . . [Y]ou could no more separate them two than you could put the brakes on a blame earthquake."1903, Frank Norris, “Two Hearts That Beat as One”, in A Deal in Wheat and Other Stories of the New and Old West
2. (idiomatic, intransitive) To cease to perform one's current activity or to decrease one's level of activity.
   • "It would have been so easy for him to have the kids rolling on the floor, doubled up with laughter. So he had to put the brakes on at times."1989 July, Nancy Griffin, “Poetry Man: Robin Williams and Dead Poets Society”, in Premiere Magazine, retrieved 31 May 2015

   Synonyms:

   rein in