Many Yemenis (5)
I believe the answer is:
arabs
'many yemenis' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for arabs that I've seen before include "Fine horses" , "Semites" , "Semitic people in the Middle East and northern Africa" , "Semitic people of the Middle East and North Africa" , "They live mainly in the Middle East and North Africa" .)