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

The researchers scanned the small patch of sky from which the neutrino likely came but saw no smoking gun such as a type of active galactic nucleus called a blazar—an immediate suspect for celestial shenanigans that scientists expect could create such a powerful particle. —Meghan Bartels, Scientific American, 12 Feb. 2025

Posner doubts the lack of a smoking gun in the final documents would fully extinguish the other theories of how and why Kennedy was killed. —Andy Rose, CNN, 25 Jan. 2025

Get yourself a cheap smoking gun and pipe smoke into a container that has the cinnamon syrup, then close the lid. —Jason O'Bryan, Robb Report, 18 Jan. 2025

There are no smoking guns in Jim’s investigation — only yearslong legal cases that hinge on technical details like the metal composition of a tiny bomb component. —Alison Herman, Variety, 2 Jan. 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