season vs spice up

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

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

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

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

season (noun)	spice up (noun)
one of the natural periods into which the year is divided by the equinoxes and solstices or atmospheric conditions
a recurrent time marked by major holidays
a period of the year marked by special events or activities in some field

season (verb)	spice up (verb)
make healthy	make more interesting or flavorful
make more temperate, acceptable, or suitable by adding something else	add herbs or spices to
lend flavor to