Definition of private eye in English:

private eye

noun

informal
  • A private investigator.

    • ‘And Donald was a great character, a detective in the classic sense of an old-school private eye detective.’
    • ‘Parker's Spenser is the best private eye in American detective fiction and has been for at least the past 20 years.’
    • ‘Jack's a hard-boiled private eye who narrates the entire film in voice-over, and who finds himself investigating an ancient Egyptian cult that worships chainsaws.’
    • ‘Tracing people is just one of the jobs private eyes take to make ends meet.’
    • ‘I thought I was watching some television detective show where the private eye puts together the clues and reveals the killer, who then admits all and is ready to be taken away.’

Pronunciation

private eye

/praɪvətˈaɪ/