thin out vs bring down

thin out and bring down both are verbs.

Word	Noun	Adjective	Verb	Adverb
thin out	No	No	Yes	No
bring down	No	No	Yes	No

As verbs, bring down is a hypernym of thin out; that is, bring down is a word with a broader meaning than thin out:

Other hypernyms of thin out include cut, cut back, cut down, reduce, trim, trim back, trim down.

thin out (verb)	bring down (verb)
make sparse	cut down on; make a reduction in
become sparser	impose something unpleasant
lessen the strength or flavor of a solution or mixture	cause to be enthusiastic
	cause to come to the ground
	move something or somebody to a lower position
	cause the downfall of; of rulers