agonistic vs agonist

agonistic is not a noun while agonist is a noun.

Word	Noun	Adjective	Verb	Adverb
agonistic	No	Yes	No	No
agonist	Yes	No	No	No

agonistic (noun)	agonist (noun)
	(biochemistry) a drug that can combine with a receptor on a cell to produce a physiological reaction
	a muscle that contracts while another relaxes
	someone involved in a contest or battle (as in an agon)
	the principal character in a work of fiction

agonistic (adjective)	agonist (adjective)
of or relating to the athletic contests held in ancient Greece
struggling for effect
striving to overcome in argument