(countable) A surname​, an Anglicization of an Irish patronymic surname based on Angus. (uncountable) A brand of dark stout beer from Ireland, one of the most widely recognised brands of beer in the world, named for Arthur Guinness who first brewed it.

What does Guinness mean?

Definitions of Guinness. a kind of bitter stout. type of: stout. a strong very dark heavy-bodied ale made from pale malt and roasted unmalted barley and (often) caramel malt with hops. English stage and screen actor noted for versatility (1914-2000)

What is the plural form of Guinness?

Guinness (plural Guinnesses) (countable) A serving of the beverage. Three Guinnesses please, barman.