a member of the British troops sent to Ireland to help put down disturbances during the Sinn Fein rebellion (1919-21)
See Black and Tan in American Heritage Dictionary 4
(blăkˈən-tănˈ)
adjective
Having a black coat with tannish markings. Used of a dog.
Involving, recognizing, or admitting Black and white people equally: a black-and-tan organization.
nounpl.Black and Tans
A member of a paramilitary force recruited in Britain and sent to Ireland as part of the Royal Irish Constabulary to suppress the Sinn Fein rebellion of 1919 to 1921.