Hangover: A common nonmedical term for the disagreeable physical effects following excessive consumption of alcohol (or the use of other psychoactive drugs). Veisalgia is the little-used medical name for the condition. Symptoms may include headache, fatigue, nausea, vomiting, and concentration difficulties.
Hangovers been known since Biblical times (or before): "Woe unto them that rise up early in the morning, that they may follow strong drink" (Isaiah 5:11).