Choose the most appropriate meaning of the given idiom.
Ace in the hole

The correct answer is A hidden advantage.

Explanation:

The idiom "Ace in the hole" refers to a major advantage, resource, or secret weapon that is kept hidden until the right time to use it to gain a favorable outcome.

Origin:

This phrase comes from stud poker, where a player's first card (often dealt face down) is known as the "hole card." Having an "ace in the hole" means holding a high-value card hidden from competitors until revealed.

Example Sentence:

"The company's strong patent portfolio proved to be their ace in the hole during the legal dispute."