A private study made of port (4)
I believe the answer is:
aden
'port' is the definition.
(port in Yemen)
'a private study' is the wordplay.
'private study' becomes 'den' (term for a study or office. I am not sure about the 'private' bit.).
'a'+'den'='ADEN'
'made of' acts as a link.
Can you help me to learn more?
(Other definitions for aden that I've seen before include "somewhere on the Arabian peninsula" , "Yemeni port" , "Dean out in the seaport city" , "Commercial capital of Yemen" , "Main port of Yemen" .)