smoking gun

noun

1. indisputable proof or evidence of a crime.

smoking gun

noun

1. a piece of irrefutable incriminating evidence

Word History and Origins

Origin of smoking gun¹

First recorded in 1970–75

Idioms and Phrases

Something that serves as indisputable evidence or proof, especially of a crime. For example, There is no smoking gun in the Oval Office; the President had no role in tampering with the evidence. This expression alludes to the smoke coming from a recently discharged firearm, a normal occurrence until the invention of smokeless powder. [Mid-1900s]

Example Sentences

"A clean signal would be a smoking gun, in my opinion," Silk said.

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Dark stars have a smoking gun signature, an absorption feature at 1640 Angstrom, due to the large amounts of singly ionized helium in their atmospheres.

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That tape became the so-called “smoking gun” evidence of a Watergate cover-up.

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“There is no one smoking gun, and I know that’s problematic for people to understand,” Barger said at a news conference Thursday.

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It may not be a proverbial smoking gun – an undeniable link to wrongdoing that destroys careers or supercharges criminal investigations.

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