Loses a game (8)
I believe the answer is:
forfeits
'loses' is the definition.
The definition and answer can be both to do with ownership as well as being verbs in their -s form.
Maybe they are linked in a way I don't understand?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for forfeits that I've seen before include "Gives up, sacrifices" , "Things paid or given as penalties" .)