The most common and most likely answer to this crossword clue is the 5 letter word BOBBY
I've seen this crossword clue in The Guardian
B
O
B
B
Y
More clues leading to the result BOBBY
Buddy explains!

The straight part
We know that "Man" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case man = bobby.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 BOBBY mean?
BOBBY noun- A police officer.
- A railway signaller.
- A penis.
- Cocaine.
- A calf that is slaughtered in its first month, usually because it has no dam or because it is undersized or otherwise defective.
- A banana that is extra small in size.