Country bordering Oman (5)
I believe the answer is:
yemen
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">country bordering oman</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for yemen that I've seen before include "Aden is found here" , "Enemy (anag) - country of Arabia" , "Middle Eastern country" , "Arabian country, capital San'a" , "Country between the Red Sea and the Gulf of Aden" .)