Extra large organ displayed around Great Britain (3,3)
I believe the answer is:
leg bye
'extra' is the definition.
(cricket term)
'large organ displayed around great britain' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'organ' becomes 'eye' (eye is a kind of organ).
'displayed around' indicates putting letters inside.
'great britain' becomes 'gb'.
'eye' enclosing 'gb' is 'egbye'.
'l'+'egbye'='LEG-BYE'
(Other definitions for leg bye that I've seen before include "Extra 24 across" , "Extra run (cricket)" , "cricketer scoring off his pad" , "Type of run (cricket)" .)