alimentary canal vs GI tract

alimentary canal and GI tract both are nouns.

Word	Noun	Adjective	Verb	Adverb
alimentary canal	Yes	No	No	No
GI tract	Yes	No	No	No

As nouns, alimentary canal and GI tract are synonyms defined as:

alimentary canal and GI 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 canal include alimentary tract, digestive tract, digestive tube, gastrointestinal tract.

alimentary canal (noun)	GI 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