What is the meaning of crow in English idiom and it's origin?

As an idiom, eating crow means you were humiliated because you were proved wrong. Presumably, eating actual crow meat is not a particularly pleasant experience. Similarly, embarrassment from misspoken Words is unpleasant for the speaker. The exact date of the first use is unclear, but it probably was first used some time around 1850 in a story about a slow-witted farmer. The similar phrase, eating one's Words, originated around 1571 when John Calvin wrote that in a gospel tract.