The most common and most likely answer to this crossword clue is the 7 letter word PISS-UP
I've seen this crossword clue in The Guardian
P
I
S
S
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U
P
Buddy explains!
The straight part
We know that "A lot of drinking" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a lot of drinking = piss-up.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 PISS-UP mean?
PISS-UP noun- A party where people consume alcohol.