crack down (on (someone/something))

to take strong action to stop something bad from continuing.

The university is taking steps to crack down on underage drinking on campus.

Countries that used to ignore terrorist groups in their midst are starting to crack down.

• at the end of the day
• at the expense of
• at the expense of something
• at the hands of
• at the hands of someone
• at the helm
• at the helm of
• at the helm of something
• at the latest
• at the mercy of
• at the mercy of someone
• at the mercy of something
• at the moment
• at the most
• at the outside
• at the point of
• at the point of something
• at the ready
• at the ripe old age of
• at the ripe old age of something
• at the top of agenda
• at the top of lungs
• at the top of someone's agenda
• at the top of the agenda
• at the top of the ladder