The most common and most likely answer to this crossword clue is the 3 plus 2 letter word LIT UP
I've seen this crossword clue in The Guardian
L
I
T
U
P
More clues leading to the result LIT UP
- Tulip surprisingly bright in display?
- Drunk was illuminating
- Parisian’s bed? Out of it is out of it
- Brahms and Liszt in the spotlight
- Plonk one liberal brought over to get thus?
- Enjoy yourself! I’ve gone out to get drunk
- Shed light on current trade union breaking record
- In middle of eclipse in Paris you appeared radiant
- Tight rim around half of cylinder
- Having had a lot of drinks, started to smoke
Buddy explains!

The straight part
We know that "drunk" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case drunk = lit 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.