Nothing in Times for young man (3)
I believe the answer is:
boy
'young man' is the definition.
(a boy is a male child)
'nothing in times' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'in' is an insertion indicator.
'times' becomes 'by' (both can mean 'multiplied by').
'o' inserted within 'by' is 'BOY'.
'for' is the link.
(Other definitions for boy that I've seen before include "Youth" , "Lad" , "Son" , "Youthful male" , "Young man" .)