private eye

American  

noun

Slang.

1. a private detective.

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private eye British  

noun

1. informal a private detective

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private eye Idioms  

1. A privately employed detective, as opposed to one working for the police or another authority. For example, The children loved stories about private eyes, and Janey wanted to become one. This expression comes from the term private investigator, the “i” of investigator being changed to “eye,” which plays on the idea of a person looking into things. [1930s]

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Etymology

Origin of private eye

1935–40; eye, allusive phonetic rendering of I, abbreviation of investigator

Example Sentences

The author of “Gravity’s Rainbow” sends a private eye on the trail of a missing heiress in a complex, comic, Prohibition-era caper.

From The Wall Street Journal • Oct. 3, 2025

The article focused on Robert Winnett, the British journalist poised to take over The Post’s newsroom in November, and described his links to a private eye who used unethical media practices to land big exclusives.

From New York Times • Jun. 17, 2024

New investigations by the district attorney’s office and the former detective turned private eye, who worked pro bono, uncovered the actual killer and the events that took place on Sept. 2, 2000.

From Los Angeles Times • Mar. 7, 2024

The great Richard Roundtree, who died this week at 81, played which private eye in five movies over a 50-year period?

From Slate • Oct. 27, 2023

During the Harding administration, in the early 1920s, the Justice Department had been packed with political cronies and unscrupulous officials, among them the head of the bureau: William Burns, the infamous private eye.

From "Killers of the Flower Moon" by David Grann

Related Words

• P.I.
• inquiry agent
• private detective
• private dick
• private investigator
• sleuth