burn down vs scorch

burn down is not a noun while scorch is a noun.

Word	Noun	Adjective	Verb	Adverb
burn down	No	No	Yes	No
scorch	Yes	No	Yes	No

As verbs, scorch is a hyponym of burn down; that is, scorch is a word with a more specific, narrower meaning than burn down:

Other hyponyms of burn down include backfire, cremate, torch.

burn down (noun)	scorch (noun)
	a discoloration caused by heat
	a surface burn
	a plant disease that produces a browning or scorched appearance of plant tissues

burn down (verb)	scorch (verb)
burn completely; be consumed or destroyed by fire	burn slightly and superficially so as to affect color
destroy by fire	make very hot and dry
	become scorched or singed under intense heat or dry conditions
	destroy completely by or as if by fire
	become superficially burned
	subject to harsh criticism