solidifying vs hardening

solidifying and hardening both are nouns.

Word	Noun	Adjective	Verb	Adverb
solidifying	Yes	No	No	No
hardening	Yes	No	No	No

As nouns, solidifying and hardening are synonyms defined as:

solidifying and hardening: the process of becoming hard or solid by cooling or drying or crystallization

Other synonyms of solidifying include curing, set, solidification.

solidifying (noun)	hardening (noun)
the process of becoming hard or solid by cooling or drying or crystallization	the act of making something harder (firmer or tighter or more compact)
	the process of becoming hard or solid by cooling or drying or crystallization
	abnormal hardening or thickening of tissue