Definition:

Scotland Yard became a synonym for British detectives in the 19th century. The phrase was generally used to refer to the Criminal Investigation Department of the London Metropolitan Police.

The name came to prominence because Scotland Yard was the location of the headquarters of the London Metropolitan Police. The actual location was a short street called Great Scotland Yard, which was located off Whitehall, in London.

The Metropolitan Police headquarters was located there from 1829-1890.