The most common and most likely answer to this crossword clue is the 8 letter word HANGOVER
I've seen this crossword clue in The Times
H
A
N
G
O
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R
More clues leading to the result HANGOVER
- Result of over-imbibing, ultimately, in royal house?
- Project for the morning after?
- Ultimately, boozing in German city results in this?
- Result of getting 19 in German city around midnight?
- European city home to heart of religious relic
- Housebound granny’s initial regret after a few sherries?
- Good visiting house, pain the morning after?
- Something from previous times, old volume, used in support of fashion
- House arrests good for headbanger?
- Depend on result of wasted time
Buddy explains!

The straight part
We know that "morning after" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case morning after = hangover.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HANGOVER mean?
HANGOVER noun- Negative effects, such as headache or nausea, caused by previous drunkenness due to (excessive) consumption of alcohol.
- Similar negative effects caused by previous excessive consumption of something else, such as a drug, coffee, sugar, etc.
- An unpleasant relic left from prior events.
- A sleeping arrangement, usually in homeless shelters, over a rope.