The most common and most likely answer to this crossword clue is the 8 letter word SWILLING
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More clues leading to the result SWILLING
Buddy explains!

The straight part
We know that "Drinking" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case drinking = swilling.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 SWILLING mean?
SWILLING verb- To drink (or, rarely, eat) greedily or to excess.
- To wash (something) by flooding with water.
- To move (a liquid or liquid-filled vessel) in a circular motion.
- (of a liquid) To move around or over a surface.
- To inebriate; to fill with drink.
- To feed swill to (pigs).
- Greedy drinking.