barley sandwich DCHP-2 (October 2016)
n. — slang, Food & Drink
a nickname for beer.
Type: 5. Frequency — The term likely originated in Canada, and is almost exclusive to Canada (see Chart 1). Barley sandwich is a humorous way to refer to beer, which is usually made from malted barley.
See also COD-2, s.v. "barley sandwich", which is marked "Cdn".
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Chart 1: Internet Domain Search, 29 Oct. 2013