put a cap on (something)
put a cap on (something)
To establish a clear upper limit for something. If we don't put a cap on rent in the city, people are going to start being put on the streets because they won't be able to afford anywhere to live. I stick to a strict budget, putting a sensible cap on how much I can spend each on non-essential things.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
put a cap on something
Fig. to put a limit on something. We need to put a cap on spending in every department. The city put a cap on the amount each landlord could charge.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.