let down vs descend

let down and descend both are verbs.

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

let down (verb)	descend (verb)
fail to meet the hopes or expectations of	come as if by falling
move something or somebody to a lower position	move downward and lower, but not necessarily all the way
	do something that one considers to be below one's dignity
	come from; be connected by a relationship of blood, for example