Land is a small nuisance (5)
I believe the answer is:
spain
'land' is the definition.
(I know that Spain is a European country)
'small nuisance' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'nuisance' becomes 'pain' (synonyms).
's'+'pain'='SPAIN'
'is a' is the link.
(Other definitions for spain that I've seen before include "holiday destination?" , "Iberian country" , "Crazy pains?" , "Kingdom" , "Catholic country" .)