The most common and most likely answer to this crossword clue is the 5 plus 5 letter word AVANT GARDE
I've seen this crossword clue in Financial Times
A
V
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More clues leading to the result AVANT GARDE
Buddy explains!
The straight part
We know that "setting the trend" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case setting the trend = avant garde.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 AVANT GARDE mean?
AVANT GARDE noun- The vanguard of an army or other force.
- Any group of people who invent or promote new techniques or concepts, especially in the arts.
- Innovative, pioneering, especially when extremely or obviously so.