Party admitting Northern Ireland exile (6)
I believe the answer is:
banish
'exile' is the definition.
(thesaurus)
'party admitting northern ireland' is the wordplay.
'party' becomes 'bash' (bash is a kind of party).
'admitting' indicates putting letters inside.
'northern ireland' becomes 'ni'.
'bash' placed around 'ni' is 'BANISH'.
(Other definitions for banish that I've seen before include "Dismiss, send away" , "Exile (someone)" , "Send (someone) away" , "Expel from a community or group" , "dislodge" .)