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

Lawrence, with Sister Agnes playing His Girl Friday, obtains the smoking gun, gives the Vatican copy machine a workout and tosses the incendiary flyers to everybody at the lunch hall.

From Salon

No smoking gun has surfaced to prove the alleged bribe actually occurred.

From Los Angeles Times

Vidal, repeating other historians’ assertions, pointed out this was “not necessarily, in those frontier days, the sign of a smoking gun — only messy male housekeeping.”

From Salon

“There’s never a smoking gun, so to speak,” Mr. Pruchnicki said.

From New York Times

Still, one legal expert said that the defense team is likely to argue there's no smoking gun yet that undoubtedly shows Trump knew about the scheme to falsify the records.

From Salon