gastrointestinal system vs liver

gastrointestinal system and liver both are nouns.

Word	Noun	Adjective	Verb	Adverb
gastrointestinal system	Yes	No	No	No
liver	Yes	Yes	No	No

gastrointestinal system (noun)	liver (noun)
the system that makes food absorbable into the body	large and complicated reddish-brown glandular organ located in the upper right portion of the abdominal cavity; secretes bile and functions in metabolism of protein and carbohydrate and fat; synthesizes substances involved in the clotting of the blood; synthesizes vitamin A; detoxifies poisonous substances and breaks down worn-out erythrocytes
	liver of an animal used as meat
	someone who lives in a place
	a person who has a special life style

gastrointestinal system (adjective)	liver (adjective)
	having a reddish-brown color