heat up vs sear

heat up is not an adjective while sear is an adjective.

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

As verbs, sear is a hyponym of heat up; that is, sear 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, scorch, bake, broil, reheat.

heat up (adjective)	sear (adjective)
	(used especially of vegetation) having lost all moisture

heat up (verb)	sear (verb)
make hot or hotter	make very hot and dry
gain heat or get hot	burn slightly and superficially so as to affect color
make more intense	cause to wither or parch from exposure to heat
	become superficially burned