Evil can spread round a Spanish city (8)
I believe the answer is:
valencia
'spanish city' is the definition.
(I've seen this before)
'evil can spread round a' is the wordplay.
'spread' indicates an anagram.
'round' is an insertion indicator.
'evil'+'can'='evilcan'
'evilcan' with letters rearranged gives 'vlencia'.
'vlencia' going around 'a' is 'VALENCIA'.
(Other definitions for valencia that I've seen before include "somewhere in Spain)" , "European area" , "Region and major port of eastern Spain" , "Spanish port" , "port in the Med" .)