Two-person contest (4)
I believe the answer is:
duel
'two-person contest' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for duel that I've seen before include "Contest to settle point of honour" , "One got satisfaction from this" , "Single combat" , "Affaire d'honneur" , "Gentlemen's disagreement" .)