Meaning of the word "Trump card" in English

What does "Trump card" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

Trump card

US /ˈtrʌmp ˌkɑːrd/
UK /ˈtrʌmp ˌkɑːd/

Noun

a powerful resource or advantage that can be used to achieve a desired outcome, especially at a crucial moment

Example:
His extensive experience in the field was his trump card during the negotiations.
The new evidence proved to be the prosecution's trump card.