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 have something that you can use to gain an advantage (in a card
game the ace is often the most valuable card and a cheater could have an ace up his or her sleeve to use against an opponent)
The football players were ready to go on strike but the team owners had an ace their sleeve and offered more money and stopped the strike.