Wrong men entered in race (4)
I believe the answer is:
tort
'wrong' is the definition.
(legal term)
'men entered in race' is the wordplay.
'men' becomes 'or' (I've seen this in other clues).
'entered in' means one lot of letters goes inside another.
'race' becomes 'tt'.
'or' placed into 'tt' is 'TORT'.
(Other definitions for tort that I've seen before include "Act for which damages can be claimed" , "A legal wrong open to claim for damages" , "Private or civil wrong - trot after it" , "Legal wrongdoing" , "Legal wrong or injury" .)