let down vs spoil

let down is not a noun while spoil is a noun.

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

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

Other hypernyms of let down include baffle, bilk, cross, foil, frustrate, queer, scotch, thwart.

let down (noun)	spoil (noun)
	the act of stripping and taking by force
	the act of spoiling something by causing damage to it
	(usually plural) valuables taken by violence (especially in war)

let down (verb)	spoil (verb)
fail to meet the hopes or expectations of	become unfit for consumption or use
move something or somebody to a lower position	alter from the original
	make imperfect
	destroy and strip of its possession
	have a strong desire or urge to do something
	hinder or prevent (the efforts, plans, or desires) of
	treat with excessive indulgence
	make a mess of, destroy or ruin