compound vs heat up

compound is a noun but heat up is not a noun.

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

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

Other hyponyms of compound include hot up, screw up, fan, enhance, heighten, raise, amplify, sharpen, heighten, sharpen.

compound (noun)	heat up (noun)
an enclosure of residences and other building (especially in the Orient)
a whole formed by a union of two or more elements or parts
a word (as anthropology, kilocycle, builder) consisting of any of various combinations of words, combining forms, or affixes.
(chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight

compound (adjective)	heat up (adjective)
composed of more than one part
consisting of two or more substances or ingredients or elements or parts
composed of many distinct individuals united to form a whole or colony

compound (verb)	heat up (verb)
put or add together	make hot or hotter
make more intense, stronger, or more marked	gain heat or get hot
combine so as to form a whole; mix	make more intense
create by mixing or combining
calculate principal and interest