heat up vs scorch

heat up is not a noun while scorch is a noun.

Word	Noun	Adjective	Verb	Adverb
heat up	No	No	Yes	No
scorch	Yes	No	Yes	No

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

Other hyponyms of heat up include crisp, crispen, toast, scald, soak, calcine, preheat, overheat, sear, bake, broil, reheat.

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

heat up (verb)	scorch (verb)
make hot or hotter	burn slightly and superficially so as to affect color
gain heat or get hot	make very hot and dry
make more intense	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