Large circle adopting northern game (5)
I believe the answer is:
bingo
'game' is the definition.
(bingo is a kind of game)
'large circle adopting northern' is the wordplay.
'large' becomes 'big' ('big' can be a synonym of 'large').
'circle' becomes 'o'.
'adopting' indicates putting letters inside.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'big'+'o'='bigo'
'bigo' going around 'n' is 'BINGO'.
(Other definitions for bingo that I've seen before include "I've completed my card!" , "Number game" , "Popular gambling game in which numbers are called at random" , "Number-calling game" , "House!" .)