To eat humble pie means to apologize humbly or to submit to humiliation.
'Humble pie' was made from the offal (or humbles) of a deer killed in a hunt. This food would be eaten by those of a lower rank in a household.
Example of use:
After showing off to his friends while driving his mother's car too fast, he had to eat humble pie when he crashed the car into a tree.
humble – (adjective) if you are humble you don't believe you are important, or you have a low opinion of yourself
humiliate – (verb) to make somebody feel worthless and without dignity or self-respect
offal – (noun) the liver, heart, kidneys etc of an animal
pie – (noun) a type of food made of fruit, vegetables or meat covered in pastry and baked.
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