regression line vs regression curve

regression line and regression curve both are nouns.

Word	Noun	Adjective	Verb	Adverb
regression line	Yes	No	No	No
regression curve	Yes	No	No	No

As nouns, regression line and regression curve are synonyms defined as:

regression line and regression curve: a smooth curve fitted to the set of paired data in regression analysis; for linear regression the curve is a straight line

regression line (noun)	regression curve (noun)
a smooth curve fitted to the set of paired data in regression analysis; for linear regression the curve is a straight line	a smooth curve fitted to the set of paired data in regression analysis; for linear regression the curve is a straight line