South Yemen port (4)
I believe the answer is:
aden
'south yemen port' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aden that I've seen before include "Dane in seaport of Yemen" , "Dean is in the Yemen, strangely" , "Yemeni port" , "Yemen's chief port" , "Strange Dane to be in the Yemen" .)