I have a hangover（this morning）.
He's still sleeping off yesterday's hangover.
1. N-COUNT If someone wakes up with a hangover, they feel sick and have a headache because they drank a lot of alcohol the night before. / disagreeable aftereffects from the use of drugs (especially alcohol) 宿醉 (过量饮酒后的恶心、头痛反应)
It was a great night and I had a massive hangover.
2. N-COUNT Something that is a hangover from the past is an idea or way of behaving which people used to have in the past but which people no longer generally have. / something that has survived from the past 遗留观念; 遗留习俗
As a hangover from rationing, they mixed butter and margarine.
hangovers from the 19th century
同近义词：residuum / morning after
【residuum】a more formal word for [residue];something left after other parts have been taken away.
【residue】A residue of something is a small amount that remains after most of it has gone. 残留物
Always using the same shampoo means that a residue can build up on the hair.