Ireland, on a euro (4)
I believe the answer is:
eire
'ireland on a euro' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eire that I've seen before include "Former name for the Republic of Ireland" , "EU country" , "Official name of the Irish Republic, 1937-49" , "Look for (something to happen)" , "Southern Ireland" .)