The most common and most likely answer to this crossword clue is the 3 letter word LAH
L
A
H
Buddy explains!

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 LAH mean?
LAH noun- A syllable used in solfège to represent the sixth note of a major scale.