clamp down vs trammel

clamp down is not a noun while trammel is a noun.

Word	Noun	Adjective	Verb	Adverb
clamp down	No	No	Yes	No
trammel	Yes	No	Yes	No

As verbs, trammel is a hypernym of clamp down; that is, trammel is a word with a broader meaning than clamp down:

Other hypernyms of clamp down include bound, confine, limit, restrict, throttle.

clamp down (noun)	trammel (noun)
	a restraint that confines or restricts freedom (especially something used to tie down or restrain a prisoner)
	a restraint that is used to teach a horse to amble
	an adjustable pothook set in a fireplace
	a fishing net with three layers; the outer two are coarse mesh and the loose inner layer is fine mesh

clamp down (verb)	trammel (verb)
repress or suppress (something regarded as undesirable)	place limits on (extent or amount or access)
	catch in or as if in a trap