Children's, Intermediate and Advanced Online English Dictionary & Thesaurus

Word Explorer
Children's Dictionary

clamp down

part of speech: phrase
definition 1: to apply strong pressure in order to hold tightly.
The dentist put a flat stick into his mouth and told him to clamp down on it with his teeth.
definition 2: (informal) to become more forceful in trying to stop behaviors that are not wanted; start using more or stronger ways of controlling.
The principal is clamping down on students being late to school. You can get into a lot more trouble now if you're late.