The most common and most likely answer to this crossword clue is the 10 letter word REMASTERED
I've seen this crossword clue in Financial Times
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More clues leading to the result REMASTERED
Buddy explains!
The straight part
We know that "improved version" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case improved version = remastered.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 REMASTERED mean?
REMASTERED verb- To produce a new version of a recording by remixing the original master recordings.
- To create a new master copy by enhancing sound or picture quality of an older recording.
- To produce a new version of a video game with updated graphics, often re-recorded music, and added features and content.
- That has been produced by remastering