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

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

Much anticipation had built up ahead of Trump’s release of the John F. Kennedy files, but observers hoping for a smoking gun were let down last month as the documents contained some new details but no key information that changed the public’s understanding of what happened. —Jared Gans, The Hill, 18 Apr. 2025

Short sellers say financial data hidden from view is an embarrassing smoking gun that the company was manipulating its public disclosures. —Christopher Helman, Forbes.com, 14 Apr. 2025

Researchers discovered two protein variants found only in other Denisovan fossils—a smoking gun for identifying which species Penghu 1 had come from. —Sarah Kuta, Smithsonian Magazine, 11 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