let down vs go down

let down and go down both are verbs.

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

let down (verb)	go down (verb)
fail to meet the hopes or expectations of	grow smaller
move something or somebody to a lower position	stop operating
	be defeated
	be ingested
	go under
	disappear beyond the horizon
	move downward and lower, but not necessarily all the way
	be recorded or remembered