Many oldtimers including my mother and grandpa called the crop a craw or crawe. They are interchangeable, but crop is a more modern name used in biology books. Here are some articles and threads about it:
https://en.m.wikipedia.org/wiki/Crop_(anatomy)
https://www.backyardchickens.com/threads/stupid-question-about-crop.597299/
https://en.m.wikipedia.org/wiki/Crop_(anatomy)
https://www.backyardchickens.com/threads/stupid-question-about-crop.597299/