Friend has a Russian fighter over initially (5)
I believe the answer is:
amigo
'friend' is the definition.
('friend' in Spanish)
'a russian fighter over initially' is the wordplay.
'russian fighter' becomes 'MiG' (Russian fighter plane manufacturer).
'initially' suggests taking the first letters.
The initial letter of 'over' is 'o'.
'a'+'mig'+'o'='AMIGO'
'has' is the link.
(Other definitions for amigo that I've seen before include "Spanish word meaning friend" , "Friend in Spanish-speaking area" , "Quixote's friend" , "Friend in Spanish-speaking areas" , "friend abroad" .)