black and tan

Wiktionary

1. n. An alcoholic beverage made from a dark and a light malt, typically Guinness or Beamish stout (black) and Bass or Harp ale (tan). In the United Kingdom, the liquids are mixed together. In the U.S., the heavier liquid fills the bottom of the glass, and the other is poured over a spoon to avoid mixing.

GNU Webster's 1913

1. adj. black mixed or spotted with tan color or reddish brown; -- used in describing certain breeds of dogs.
2. adj. See under Black, a.

WordNet 3.0

1. n. an English recruit (who wore a uniform that was black and tan) serving in the Irish constabulary to suppress the Sinn Fein rebellion of 1919 to 1921