flavour vs spice up

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

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

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

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

flavour (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

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