The most common and most likely answer to this crossword clue is the 7 letter word TIPPLER
I've seen this crossword clue in The Guardian
T
I
P
P
L
E
R
More clues leading to the result TIPPLER
Buddy explains!

The straight part
We know that "Drunkard" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case drunkard = tippler.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 TIPPLER mean?
TIPPLER noun- (Webster 1913) A seller of alcoholic liquors; keeper of a tippling-house.
- A habitual drinker; a bibber.
- A breed of domestic pigeon bred to participate in endurance competitions.
- An open wagon with a tipping trough, unloaded by being inverted (used for bulk cargo, especially minerals). A mine car, a lorry.
- One who works at a tipple.