Yemeni seaport (4)
I believe the answer is:
aden
'yemeni seaport' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for aden that I've seen before include "Former Br. Gulf colony" , "Dane in seaport of Yemen" , "Yemen's chief port" , "Dean is out in the Middle Eastern port" , "Dean out in the seaport city" .)