Be equal in a game (5)
I believe the answer is:
match
This clue is a triple definition!
'be' is the first definition.
(I know that match is a more specific form of the action be)
'equal' is the second definition.
(matching is a kind of equaling)
'in' is a link.
'a game' is the third definition.
(eg a football match)
(Other definitions for match that I've seen before include "Marriage; game" , "Contest; correspond" , "Contest; pair" , "Alliance" , "Equal contender" .)