ace in the hole

Definition

Synonym of ace up one's sleeve.

Etymology

From stud poker in which there is one unknown card called the hole card, referring to the optimum hole card being an ace.

Example Sentences

• "Our ace in the hole left our opponents stupefied; it isn't every day that an NBA star plays street basketball."
• "You didn't think I'd risk losing the battle for Gotham's soul in a fistfight with you? No. You need an ace in the hole. Mine's Harvey."