Love letter to Northern Ireland (3)
I believe the answer is:
nil
'love' is the definition.
(love and nil mean zero in cricket and football)
'letter to northern ireland' is the wordplay.
'letter' becomes 'l' ().
'to' means one lot of letters go next to another (I've seen this in other clues).
'northern ireland' becomes 'NI' (abbreviation).
'l' after 'ni' is 'NIL'.
(Other definitions for nil that I've seen before include "none" , "Nix, nada, nothing" , "Score of nought" , "Nothing, naught" , "duck" .)