I’m told one might long for a port (4)
I believe the answer is:
acre
'for a port' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for acre that I've seen before include "Crusaders battlefield, now in Israel" , "marine location in Israel" , "4840 sq yds" , "region of ground" , "Unit of land area" .)