It was 'Barley Mow' by the end of the 18th century, Michael. At least 2 quite different broadsides.

The 1609 (Deutromelia) with tune version doesn't include any personnel except for the butler (bottler). It's all drink measures but accumulative like most modern versions.

I drink very little myself nowadays.

Your dictionary entry says 'noun archaic'. Wonder how far back the phrase/word can actually be traced. If it is indeed old then it's easy to see how quickly 'bella moy' would become 'barley mow' amongst the plebs like me.