curvilinear correlation vs nonlinear correlation

curvilinear correlation and nonlinear correlation both are nouns.

Word	Noun	Adjective	Verb	Adverb
curvilinear correlation	Yes	No	No	No
nonlinear correlation	Yes	No	No	No

As nouns, curvilinear correlation and nonlinear correlation are synonyms defined as:

curvilinear correlation and nonlinear correlation: any correlation in which the rates of change of the variables is not constant

Other synonyms of curvilinear correlation include skew correlation.

curvilinear correlation (noun)	nonlinear correlation (noun)
any correlation in which the rates of change of the variables is not constant	any correlation in which the rates of change of the variables is not constant