private eye

American  

noun

Slang.

1. a private detective.

---

private eye British  

noun

1. informal a private detective

---

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]

---

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 late, great Raymond Chandler and his private eye live on as potential IP for new books, video games, TV projects, graphic novels and more.

From Los Angeles Times • Dec. 10, 2024

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

“The New York Trilogy,” which included “City of Glass,” “Ghosts” and “The Locked Room,” was a postmodern detective saga in which names and identities blur and one protagonist is a private eye named Paul Auster.

From Seattle Times • May 1, 2024

No one had aroused more suspicion than the private eye called Pike.

From "Killers of the Flower Moon" by David Grann

Related Words

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