hangover | noun

Kater m
Katerstimmung f

Headaches that results from an excess of alcohol.
Kopfschmerzen, die durch einen übermäßigen Alkoholkonsum entstehen.

A hangover is the experience of various unpleasant physiological and psychological effects usually following the consumption of alcohol, such as wine, beer, and distilled spirits. Hangovers can last for several hours or for more than 24 hours.
Wikipedia

Synonym: headache, head