Land before one is accepted (4)
I believe the answer is:
eire
'land' is the definition.
(Eire is an example)
'before one is accepted' is the wordplay.
'before' becomes 'ere' (usually literary).
'one' becomes 'i' (Roman numeral).
'is accepted' means one lot of letters goes inside another.
'ere' placed around 'i' is 'EIRE'.
(Other definitions for eire that I've seen before include "Southern Ireland" , "Northwest European country" , "Official name of the Irish Republic, 1937-49" , "Look for (something to happen)" , "Irish name for Ireland" .)