skull-splitter

Noun

skull splitter (plural skull splitters)

1. A severe headache or migraine.
   • Indeed, in many villages, the wine store is called Can Vinagre even today; the vinegar house, where wine is sold in the customer's own plastic bottles from great vats of wine, and it is a matter of luck whether you take away an astonishing vintage or a skull-splitter.2000, Gunter Beer, Carlos Agustin and Belen Tanago, “From skull-splitters to top wines Binissalem”, in Majorca : culture and life, page 158
2. (slang) Any highly potent alcoholic beverage, mixed drink, or knock-off spirit designed to give the drinker a severe hangover.
   • You don't want that at this time of day; that's a skull splitter.1985, Heinlein, Robert A. (Robert Anson), 1907-1988, Job : a comedy of justice, page 50