specialize vs specialist

specialize is not a noun while specialist is a noun.

Word	Noun	Adjective	Verb	Adverb
specialize	No	No	Yes	No
specialist	Yes	No	No	No

specialize (noun)	specialist (noun)
	an expert who is devoted to one occupation or branch of learning
	practices one branch of medicine

specialize (verb)	specialist (verb)
become more focused on an area of activity or field of study
suit to a special purpose
evolve so as to lead to a new species or develop in a way most suited to the environment
be specific about
devote oneself to a special area of work