Something corny cut by Irish writer, one from Dublin or Antrim? (9)
I believe the answer is:
easterner
'one from dublin or antrim?' is the definition.
(someone from the east of Ireland)
'something corny cut by irish writer' is the wordplay.
'something corny' becomes 'ear' (as in an ear of corn).
'cut by' indicates putting letters inside (some letters cut into others).
'irish writer' becomes 'Sterne' (18th-century novelist Laurence Sterne).
'ear' placed around 'sterne' is 'EASTERNER'.
(Other definitions for easterner that I've seen before include "resident of New Jersey?" , "Oriental person" , "Resident of Connecticut, perhaps" , "one from Boston, say" , "Asian" .)