Devil's buttermilk

n.

Devil's buttermilk is Irish slang for a pint of porter or stout. The old black stuff.

In use

Pour me a devil's buttermilk there like a good man.

Let Lawrence Muck translate it to posh English for you
Lawrence Muck

Hello, and please excuse the hounds. Would you like me to translate 'Devil's buttermilk' in use for you?

Do be a good fellow and pour me a pint of stout.

Questions

What does devil's buttermilk mean in Ireland?

A pint of porter or stout. The old black stuff.

How do you use devil's buttermilk in a sentence?

“Pour me a devil's buttermilk there like a good man.”

Updated