let down vs bring down

let down and bring down both are verbs.

Word	Noun	Adjective	Verb	Adverb
let down	No	No	Yes	No
bring down	No	No	Yes	No

As verbs, let down and bring down are synonyms defined as:

Other synonyms of let down include get down, lower, take down.

let down (verb)	bring down (verb)
fail to meet the hopes or expectations of	cut down on; make a reduction in
move something or somebody to a lower position	impose something unpleasant
	cause to be enthusiastic
	cause to come to the ground
	move something or somebody to a lower position
	cause the downfall of; of rulers