Thwart in game (7)
I believe the answer is:
snooker
This could be a double definition.
'thwart' is the first definition.
The definition and answer can be both to do with social activities as well as being verbs in their base form.
Perhaps there's a link between them I don't understand?
'game' is the second definition.
(snooker is a game)
'in' acts as a link.
Can you help me to learn more?
(Other definitions for snooker that I've seen before include "Cue sport" , "Potting game" , "Stymie" , "A percussion instrument" , "Game played on a billiards table" .)