Land one, punching Hilary (5)
I believe the answer is:
benin
'land' is the definition.
(Benin is an example)
'one punching hilary' is the wordplay.
'one' becomes 'i' (roman numeral).
'punching' means one lot of letters goes inside another (I've seen this in other clues).
'hilary' becomes 'benn' (politician Hilary Benn).
'i' placed into 'benn' is 'BENIN'.
(Other definitions for benin that I've seen before include "West African state, formerly called Dahomey" , "Country W. of Nigeria" , "West African country, formerly French colony of Dahomey" , "East African state" , "West Africa country, formerly a French colony" .)