Southernmost part of Arabia (5)
I believe the answer is:
yemen
'southernmost part of arabia' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for yemen that I've seen before include "Republic on the Arabian Peninsula" , "nation" , "Arabian republic, capital Sanaa" , "Enemy (anag) - country of Arabia" , "Arab state" .)