regression analysis vs regression toward the mean

regression analysis and regression toward the mean both are nouns.

Word	Noun	Adjective	Verb	Adverb
regression analysis	Yes	No	No	No
regression toward the mean	Yes	No	No	No

regression analysis (noun)	regression toward the mean (noun)
the use of regression to make quantitative predictions of one variable from the values of another	the relation between selected values of x and observed values of y (from which the most probable value of y can be predicted for any value of x)