alimentary vs nutrient

alimentary is not a noun while nutrient is a noun.

Word	Noun	Adjective	Verb	Adverb
alimentary	No	Yes	No	No
nutrient	Yes	Yes	No	No

As adjectives, alimentary and nutrient are synonyms defined as:

Other synonyms of alimentary include alimental, nourishing, nutritious, nutritive.

alimentary (noun)	nutrient (noun)
	any substance that can be metabolized by an animal to give energy and build tissue
	any substance (such as a chemical element or inorganic compound) that can be taken in by a green plant and used in organic synthesis

alimentary (adjective)	nutrient (adjective)
of or providing nourishment	of or providing nourishment