Answer: barleycorn

AnswerCrossword Clue
BARLEYCORNSubject of Burns poem.
BARLEYCORNWhisky.
BARLEYCORNJohn ....
BARLEYCORNBeverage of a kind.
BARLEYCORNSir John of old song.
BARLEYCORNJohn
BARLEYCORNBurns celebrated this John
BARLEYCORNMalt liquor base
barleycornA grain of barley
barleycornan old unit of length equal to one-third inch
barleycornA former unit of measurement (about a third of an inch) based on the length of a grain of barley