Nation has terrible rain (4)
I believe the answer is:
iran
'nation' is the definition.
(Iran is an example)
'terrible rain' is the wordplay.
'terrible' is an anagram indicator.
'rain' anagrammed gives 'IRAN'.
'has' is the link.
(Other definitions for iran that I've seen before include "Persia some time ago" , "Rain (anag) - country" , "Iraq's neighbour" , "Country lying to south of Caspian sea" , "Tehran's country" .)