The most common and most likely answer to this crossword clue is the 7 letter word PUPPIES
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More clues leading to the result PUPPIES
Buddy explains!

The straight part
We know that "Young setters possibly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case young setters possibly = puppies.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 PUPPIES mean?
PUPPIES noun- A young dog, especially before sexual maturity (12-18 months)
- A young rat.
- A young seal.
- (usually in the plural) A woman’s breast.
- A (generic) thing; particularly something that is a nuisance; a sucker.
- A conceited and impertinent person, especially a young man.
- To bring forth whelps or give birth to pups.