relativity vs relativistic

relativity is a noun but relativistic is not a noun.

Word	Noun	Adjective	Verb	Adverb
relativity	Yes	No	No	No
relativistic	No	Yes	No	No

relativity (noun)	relativistic (noun)
the quality of being relative and having significance only in relation to something else
(physics) the theory that space and time are relative concepts rather than absolute concepts

relativity (adjective)	relativistic (adjective)
	relating or subject to the special or the general theory of relativity
	of or relating to the philosophical doctrine of relativism