smoking gun

noun

: something that serves as conclusive evidence or proof (as of a crime or scientific theory)

Examples of smoking gun in a Sentence

This document is the smoking gun that proves that he was lying.

Recent Examples on the Web

But there’s no smoking gun, no official designation, no bronze plaque. —David Hudnall, Kansas City Star, 30 June 2025

My point here is there no conclusive smoking gun in the literature about difference in tolerance between boys and girls that might explain my speculative observations. —Marshall Shepherd, Forbes.com, 29 June 2025

In the tale of two realities, the prosecution has essentially treated the footage, portions of which were exclusively aired on CNN back in the spring of 2024, as a smoking gun. —Dominic Patten, Deadline, 19 May 2025

In 2024 a big news story emerged purporting to finally offer the smoking gun evidence proving once and for all that private conversations are tracked by smartphones to tailor ads to individual users. —New Atlas, 24 Apr. 2025

Word History

First Known Use

1974, in the meaning defined above

Rhymes for smoking gun

• anyone
• everyone
• megaton
• overdone
• overrun
• povidone
• trazodone
• begun
• grandson
• gudrun
• handgun
• homespun