Applauding picking for international match outside left (8)
I believe the answer is:
clapping
'applauding' is the definition.
('clap' can be a synonym of 'applaud')
'picking for international match outside left' is the wordplay.
'picking for international match' becomes 'capping' (to cap a player is to put them in a national team).
'outside' indicates putting letters inside.
'left' becomes 'L' (common abbreviation).
'capping' placed around 'l' is 'CLAPPING'.
(Other definitions for clapping that I've seen before include "Applause" , "Applauding" .)