Scar shown by Arab (5)

I believe the answer is:

saudi

'arab' is the definition.
(someone from Saudi Arabia)

I don't understand the remainder of the clue.

(Other definitions for saudi that I've seen before include "Native of Riyadh, perhaps" , "Eg, native of Riyadh" , "from the Middle East" , "one accustomed to hot, dry conditions?" , "Arab" .)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app