Enemy destroyed one Arab native (6)
I believe the answer is:
yemeni
'arab native' is the definition.
'yemeni' can be an answer for 'native' (I have seen 'Native of Aden ' mean 'yemeni' so perhaps 'native' could also mean 'yemeni'). I am not certain of the 'arab' bit.
'enemy destroyed one' is the wordplay.
'destroyed' indicates anagramming the letters.
'one' becomes 'i' (Roman numeral).
'enemy' anagrammed gives 'yemen'.
'yemen'+'i'='YEMENI'
Can you help me to learn more?
(Other definitions for yemeni that I've seen before include "Person from Aden perhaps" , "Arab national" , "from an Arab country" , "language" , "Someone from Aden?" .)