systematics vs systematist

systematics and systematist both are nouns.

Word	Noun	Adjective	Verb	Adverb
systematics	Yes	No	No	No
systematist	Yes	No	No	No

systematics (noun)	systematist (noun)
the science of systematic classification	a biologist who specializes in the classification of organisms into groups on the basis of their structure and origin and behavior
	an organizer who puts things in order