He soon has nothing to lose (3)
I believe the answer is:
son
'he' is the definition.
'soon has nothing to lose' is the wordplay.
'has nothing' becomes 'o' (I've seen this in other clues).
'to lose' is a deletion indicator.
'soon' with 'o' taken out is 'SON'.
(Other definitions for son that I've seen before include "Human offspring" , "Male child" , "Heir" , "The kind of child" , "Express paper" .)