ventriculus vs gastric mill

ventriculus and gastric mill both are nouns.

Word	Noun	Adjective	Verb	Adverb
ventriculus	Yes	No	No	No
gastric mill	Yes	No	No	No

As nouns, ventriculus and gastric mill are synonyms defined as:

ventriculus and gastric mill: thick-walled muscular pouch below the crop in many birds and reptiles for grinding food

Other synonyms of ventriculus include gizzard.

ventriculus (noun)	gastric mill (noun)
thick-walled muscular pouch below the crop in many birds and reptiles for grinding food	thick-walled muscular pouch below the crop in many birds and reptiles for grinding food