dimensional vs dimension

dimensional is not a noun while dimension is a noun.

Word	Noun	Adjective	Verb	Adverb
dimensional	No	Yes	No	No
dimension	Yes	No	Yes	No

dimensional (noun)	dimension (noun)
	the magnitude of something in a particular direction (especially length or width or height)
	magnitude or extent
	a construct whereby objects or individuals can be distinguished
	one of three Cartesian coordinates that determine a position in space

dimensional (adjective)	dimension (adjective)
of or relating to dimensions
having dimension--the quality or character or stature proper to a person

dimensional (verb)	dimension (verb)
	shape or form to required dimensions
	indicate the dimensions on