flavor vs spice up

flavor is a noun but spice up is not a noun.

Word	Noun	Adjective	Verb	Adverb
flavor	Yes	No	Yes	No
spice up	No	No	Yes	No

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

Other hyponyms of flavor include sauce, curry, resinate, spice, zest, savor, savour, salt.

flavor (noun)	spice up (noun)
the taste experience when a savoury condiment is taken into the mouth
(physics) the six kinds of quarks
the general atmosphere of a place or situation and the effect that it has on people

flavor (verb)	spice up (verb)
lend flavor to	make more interesting or flavorful
	add herbs or spices to