Proper noun

1. for someone from a place of that name near Dunbar.
2. Allan Pinkerton (1819-1884), Scottish-born founder of a American detective agency involved in early anti-union and strikebreaking activity.
3. An operative employed by the Pinkerton National Detective Agency.
   • 1950, "Kiss the Donkey," Time, 4 Sep.,

     He joined the pickets in the bloody Homestead steel strike of 1892, and actually went so far as to jostle a Pinkerton.