Ladies' group -- function we run for a man on his own, perhaps (7)
I believe the answer is:
widower
'a man on his own perhaps' is the definition.
'ladies' group function we run' is the wordplay.
'ladies' group' becomes 'wi'.
'function' becomes 'do' (I've seen this in other clues).
'run' becomes 'r' (cricket abbreviation).
'wi'+'do'+'we'+'r'='WIDOWER'
'for' acts as a link.
(Other definitions for widower that I've seen before include "One who has lost wife" , "Man who has lost his wife" , "His wife is deceased" , "Man whose wife has died" , "Man left" .)