Dictionary.com
definitions

John Barleycorn

noun
  1. a personification of barley as used in malt liquor, of malt liquor itself, or of any intoxicating liquor.

Origin of John Barleycorn

First recorded in 1610–20
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for john barleycorn

John Barleycorn

noun
  1. usually jocular the personification of alcohol, esp of malt spirits
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012