The most common and most likely answer to this crossword clue is the 5 letter word BENNY
I've seen this crossword clue in Independent
B
E
N
N
Y
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 = benny.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 BENNY mean?
BENNY noun- An amphetamine tablet.
- A tantrum; a fit of furious or erratic behaviour.
- (usually with "up") To take amphetamines.
- A benefit.
- An overcoat.
- A straw hat.
- (originally United States) A dish consisting of slices of English muffins with poached eggs, ham or bacon and hollandaise sauce.