Eating crow is a colloquial idiom used by many Americans.
What does "eating crow" mean?
Eating crow means someone is humiliated by admitting wrongness or having been proven wrong after taking a strong position.
A crow is presumably foul-tasting in the same way that being proven wrong might be emotionally hard to swallow. Eating crow is thought of as being distasteful.
Why is the expression about a crow instead of an eagle, owl, hawk or another bird?
The crow is one of the birds listed in Leviticus 11:13-19 as being unclean and unfit for eating. Along with buzzards, rats, and other carrion-eating scavenging animals, there is a tradition in Western culture going back to the Middle Ages of seeing them as distasteful and even illegal to eat. Therefore, it is naturally humiliating if forced to consume crow against one's will.
Eating crow is similar to "eating one's own words."
The following story is about eating crow that dates back to 1885.
Rudyard Kipling used the concept as a central metaphor in his short story "The Strange Ride of Morrowbie Jukes" written in 1885. The main character, Morrowbie Jukes, a European colonist in India, falls into a sand-pit from which he cannot escape. Another man, a native Indian, is also trapped there who catches wild crows and eats them. Morrowbie has too much pride to eat crows. Therefore, he declares, "I shall never eat crow!" After days of having nothing to eat, Morrowbie became so hungry and desperate that he finally was forced to do what he swore he would never do. He ate crow.
Be careful with your words. If not, you might find yourself eating crow.