The most common and most likely answer to this crossword clue is the 4 letter word BOYS
I've seen this crossword clue in The Guardian
B
O
Y
S
More clues leading to the result BOYS
Buddy explains!

The straight part
We know that "Y/oung men" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case y/oung men = boys.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 BOYS mean?
BOYS noun- A young male.
- (diminutive) A male child: a son of any age.
- (diminutive) A male of any age, particularly one rather younger than the speaker.
- A male of low station, (especially as pejorative) a worthless male, a wretch; a mean and dishonest male, a knave.
- (now rare and usually offensive outside some Commonwealth nations) A male servant, slave, assistant, or employee, particularly:
- Any non-white male, regardless of age.
- A male animal, especially, in affectionate address, a male dog.
- A former low rank of various armed services; a holder of this rank.
- Heroin.
- (somewhat childish) A male (tree, gene, etc).
- The testicles.