Ring smuggled Algerian port (4)
I believe the answer is:
oran
'algerian port' is the definition.
(I've seen this in another clue)
'ring smuggled' is the wordplay.
'ring' becomes 'O' (O is the shape of a ring).
'smuggled' becomes 'ran' (to run something is to smuggle it).
'o'+'ran'='ORAN'
(Other definitions for oran that I've seen before include "African port" , "Algerian seaport" , "Algerian port" .)