private eye

A private eye is a detective who works for private customers, rather than with a police department. If a local dog thief steals your poodle, you might want to hire a private eye to investigate.

The informal private eye comes from private investigator and its frequent shorthand, PI. Private eyes are probably most common in detective novels, although they are frequently hired (in real life) by lawyers to investigate suspicious insurance claims and divorce cases. Investors sometimes hire private eyes to examine businesses before they invest money, too. The earliest known private eye set up shop in 1830s France.

Definitions of private eye
1

n someone who can be employed as a detective to collect information

Synonyms:
PI, operative, private detective, private investigator, shamus, sherlock
Types:
hotel detective, house detective, house dick
a private detective employed by a hotel or retail store
inquiry agent
a private detective
store detective
a private detective employed by a merchant to stop pilferage
Type of:
detective
an investigator engaged or employed in obtaining information not easily available to the public

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