clamp down on

clamp down on (someone or something)

1. Literally, to press down on something firmly. When the dog's teeth clamped down on my leg, I'd never felt so much pain in my life. Now clamp down on this surface so that you don't lose your grip while drilling.
2. To limit, reduce, bring under tighter control. My parents really clamped down on me after seeing my report card, so my curfew is only 9 PM now. We really need to clamp down on spending before our department loses funding altogether. The cops are trying to clamp down on speeding on this stretch, so you should slow down.
See also: clamp, down, on
Farlex Dictionary of Idioms.

clamp down on

Also, put the clamps on. Become stricter or more repressive; put a stop to. For example, The company was clamping down on expenses like business lunches, or It's time we put the clamps on polluters. [Mid-1900s]
See also: clamp, down, on
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • clamp down
  • clamp down on (someone or something)
  • be down to (do something)
  • be down to something
  • bear down on (someone or something)
  • come a gutser
  • chomp down on (someone or something)
  • come down with
  • be down to (one)
  • be down to somebody/something