Young men or unruly yobs? (4)
I believe the answer is:
boys
'young men' is the definition.
(I've seen this before)
'unruly yobs?' is the wordplay.
'unruly' indicates an anagram.
'yobs' anagrammed gives 'BOYS'.
'or' is the link.
(Other definitions for boys that I've seen before include "Young men" , "Young males" , "Beach --, group" , "They will be themselves, it's said" , "Male children" .)