The most common and most likely answer to this crossword clue is the 4 letter word BOUT
I've seen this crossword clue in The Guardian
B
O
U
T
More clues leading to the result BOUT
- Nothing stops just fight
- British elimination in contest
- Close to cancelling amateur fight
- Roughly losing head in a fight
- Fight roughly, the first to be thrown out
- Bowled, dismissed in match
- Sporting contest, though there’s nothing in it
- Fight roughly, getting head knocked off
- Fight, still holding ring
- Fit period in ring
Buddy explains!

The straight part
We know that "a fight" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a fight = bout.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 BOUT mean?
BOUT noun- A period of something, usually painful or unpleasant.
- A boxing match.
- An assault (a fencing encounter) at which the score is kept.
- A roller derby match.
- A fighting competition.
- A bulge or widening in a musical instrument, such as either of the two characteristic bulges of a guitar.
- The going and returning of a plough, or other implement used to mark the ground and create a headland, across a field.
- To contest a bout.
- In a circle around; all round; on every side of; on the outside of.
- Over or upon different parts of; through or over in various directions; here and there in; to and fro in; throughout.
- Indicates that something will happen very soon; indicates a plan or intention to do something.
- Concerning; with regard to; on account of; on the subject of; to affect.
- Concerned with; engaged in; intent on.
- Within or in the immediate neighborhood of; in contiguity or proximity to; near, as to place.
- On one's person; nearby the person.
- In or near, as in mental faculties or in the possession of; under the control of; at one's command; in one's makeup.