smoking gun

American  

noun

1. indisputable proof or evidence of a crime.

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smoking gun British  

noun

1. a piece of irrefutable incriminating evidence

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smoking gun Idioms  

1. 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]

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Etymology

Origin of smoking gun

First recorded in 1970–75

Example Sentences

There is no definitive smoking gun in this lawsuit.

From BBC

With crypto, you rarely need a smoking gun — leverage and narrative do the job.

From MarketWatch

Scott Griffiths of the Melbourne School of Psychological Sciences said a "smoking gun research study" was unlikely to emerge soon to prove the harms of social media.

From Barron's

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

From Science Daily

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.

From Science Daily