specializer vs specialist

specializer and specialist both are nouns.

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

As nouns, specializer and specialist are synonyms defined as:

specializer and specialist: an expert who is devoted to one occupation or branch of learning

Other synonyms of specializer include specialiser.

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