Certain kind of Russian should avoid south of Portugal? (7)
I believe the answer is:
iberian
'of portugal?' is the definition.
(Iberia consists of Spain and Portugal)
'certain kind of russian should avoid south' is the wordplay.
'certain kind of russian' becomes 'siberian'.
'should avoid' suggests deleting specific letters.
'south' becomes 's' ('S' can be a synonym of 'south').
'siberian' with 's' taken away is 'IBERIAN'.
(Other definitions for iberian that I've seen before include "Relating to the Spanish peninsula" , "Person from Spain or Portugal" , "from Malaga?" , "one from Spain, perhaps" , "An old European" .)