Horned animal seen in European country (5)
I believe the answer is:
eland
'horned animal' is the definition.
(eland is a type of antelope)
'european country' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'country' becomes 'land' (synonyms).
'e'+'land'='ELAND'
'seen in' is the link.
(Other definitions for eland that I've seen before include "Spiral-horn antelope" , "Led an (anag) -- antelope" , "One browses in the African plain" , "African mammal" , "Browser" .)