The most common and most likely answer to this crossword clue is the 4 letter word JUST
J
U
S
T
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 JUST mean?
JUST adjective- Factually right, correct; factual.
- Rationally right, correct.
- Morally right; upright, righteous, equitable; fair.
- Proper, adequate.
- Only, simply, merely.
- (sentence adverb) Used to reduce the force of an imperative; simply.
- Used to convey a less serious or formal tone
- Used to show humility.
- (degree) absolutely, positively
- Moments ago, recently.
- By a narrow margin; closely; nearly.
- Exactly, precisely, perfectly.
- Expressing dismay or discontent.
- A joust, tournament.
- To joust, fight a tournament.