season vs harden

season is a noun but harden is not a noun.

Word	Noun	Adjective	Verb	Adverb
season	Yes	No	Yes	No
harden	No	No	Yes	No

As verbs, season and harden are synonyms defined as:

season (noun)	harden (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)	harden (verb)
make healthy	become hard or harder
make more temperate, acceptable, or suitable by adding something else	make hard or harder
lend flavor to	make healthy
	cause to accept or become hardened to; habituate
	harden by reheating and cooling in oil