Meaning of the word "smoking gun" in English

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

smoking gun

US /ˈsmoʊkɪŋ ɡʌn/
UK /ˈsmoʊkɪŋ ɡʌn/
"smoking gun" picture

Idiom

irrefutable evidence of a crime or wrongdoing

Example:
The security footage was the smoking gun that proved his involvement in the robbery.
Investigators are still searching for the smoking gun in the corruption case.