The most common and most likely answer to this crossword clue is the 5 letter word QUITS
I've seen this crossword clue in The Daily Telegraph
Q
U
I
T
S
Buddy explains!
The straight part
We know that "Square/leaves" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case square/leaves = quits.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 QUITS mean?
QUITS verb- To pay (a debt, fine etc.).
- To repay (someone) for (something).
- To repay, pay back (a good deed, injury etc.).
- To conduct or acquit (oneself); to behave (in a specified way).
- To carry through; to go through to the end.
- To set at rest; to free, as from anything harmful or oppressive; to relieve; to clear; to liberate.
- To release from obligation, accusation, penalty, etc.; to absolve; to acquit.
- To abandon, renounce (a thing).
- To leave (a place).
- To resign from (a job, office, position, etc.).
- To stop, give up (an activity) (usually + gerund or verbal noun).
- To close (an application).
- On equal monetary terms; neither owing or being owed.
- Any of numerous species of small passerine birds native to tropical America.