specialiser vs specialist

specialiser and specialist both are nouns.

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

As nouns, specialiser and specialist are synonyms defined as:

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

Other synonyms of specialiser include specializer.

specialiser (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