The most common and most likely answer to this crossword clue is the 5 letter word AMEND
I've seen this crossword clue in Financial Times
A
M
E
N
D
More clues leading to the result AMEND
- Correct interpretation of noon?
- Change commercial about workers
- Better sort of dash back — joiner’s outside
- Make a change to last word, fourth letter
- Improve, with this person intervening
- Alter the last word at end of screed
- Revise commercial involving soldiers
- Make small improvements to a motorway before completion
- Change objective having lost heart before the finish
- Mark tucks into a scotch — that’s better
Buddy explains!

The straight part
We know that "to improve" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to improve = amend.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 AMEND mean?
AMEND noun- (usually in the plural) An act of righting a wrong; compensation.
- To make better; improve.
- To become better.
- To heal (someone sick); to cure (a disease etc.).
- To be healed, to be cured, to recover (from an illness).
- To make a formal alteration (in legislation, a report, etc.) by adding, deleting, or rephrasing.