alimentary tract vs gastrointestinal tract

alimentary tract and gastrointestinal tract both are nouns.

Word	Noun	Adjective	Verb	Adverb
alimentary tract	Yes	No	No	No
gastrointestinal tract	Yes	No	No	No

As nouns, alimentary tract and gastrointestinal tract are synonyms defined as:

alimentary tract and gastrointestinal tract: tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination

Other synonyms of alimentary tract include alimentary canal, digestive tract, digestive tube, GI tract.

alimentary tract (noun)	gastrointestinal tract (noun)
tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination	tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination