mature vs fossilize

mature is an adjective but fossilize is not an adjective.

Word	Noun	Adjective	Verb	Adverb
mature	No	Yes	Yes	No
fossilize	No	No	Yes	No

As verbs, fossilize is a hyponym of mature; that is, fossilize is a word with a more specific, narrower meaning than mature:

Other hyponyms of mature include turn, fossilise, dote.

mature (adjective)	fossilize (adjective)
having reached full natural growth or development
characteristic of maturity
(of birds) having developed feathers or plumage; often used in combination
fully developed or matured and ready to be eaten or used
fully considered and perfected

mature (verb)	fossilize (verb)
cause to ripen and discharge pus	convert to a fossil
develop and reach maturity; undergo maturation	become mentally inflexible
grow old or older
become due for repayment
cause to ripen or develop fully
develop and work out fully in one's mind