sherlock

noun Informal.

1. a private detective.
2. a person remarkably adept at solving mysteries, especially by using insight and logical deduction: Who’s the sherlock who can tell me where my pen is?

noun

1. a male given name: from an Old English word meaning “fair-haired.”

masc. proper name, literally “fair-haired,” from Old English scir “bright” + locc “lock of hair.” Slang for “private detective, perceptive person” (the latter often ironic) is attested from 1903, from A.C. Doyle’s fictional character Sherlock Holmes (full name in this sense used from 1896; Holmes debuted in 1887 and was popular by 1892).