noun
- Allan,1819–84, U.S. detective, born in Scotland.
noun
- Allan. 1819–84, US private detective, born in Scotland. He founded the first detective agency in the US (1850) and organized an intelligence system for the Federal States of America (1861)
n.“semi-official detective,” 1888, from the detective agency begun in U.S. 1850 by Allan Pinkerton (1819-1884).