Synonyms:
private_detective, PI, private_eye, private_investigator, operative, shamus, sherlock
Meaning: someone who can be employed as a detective to collect information
Usage examples
What would Sherlock Holmes have done?
I promise you that," said Sherlock Holmes.
"It seems a singularly useless thing to steal," said Sherlock Holmes. "I confess that I share Dr. Mortimer's belief that it will not be long before the missing boot is found."