The most common and most likely answer to this crossword clue is the 12 letter word ALCOHOL-FREE
I've seen this crossword clue in The Guardian
A
L
C
O
H
O
L
-
F
R
E
E
Buddy explains!

The straight part
We know that "dry" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dry = alcohol-free.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 ALCOHOL-FREE mean?
ALCOHOL-FREE adjective- Containing no alcohol.