Meaning

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

originSupposedly from an Old English scir-locc (“bright-lock”). One of a group of surnames originally denoting hair colour, parallel to Blacklock, Harlock (Old English har (“grey”)), Silverlock. In the sense of “a detective”, from Sherlock Holmes. In the computing verb sense, refers to the software Sherlock, which in 2002 came to replicate some of the features of an earlier complementary program called…

Etymology from Wiktionary, CC BY-SA 3.0