This
database is a comprehensive collection of all the American idioms and slang available.
American Idioms are many and varied. We hope you enjoy our collection. We are adding more all the time.
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To do something nice or kind to someone who has been nasty to you. If someone felt bad because they forgot to get you a Christmas gift, for you to buy them a specially nice gift is heaping coals on their head. ('Heap coals of fire' is also used.)