Port (5)
'port' is the definition.
(I know that harbour is a type of port)
This is the entire clue.
(Other definitions for harbour that I've seen before include "Sheltered port" , "Shelter for ships" , "Keep (thought) secretly (in one's mind); haven" , "mole" , "Bear" .)
(Other definitions for parallel that I've seen before include "Maintaining distance apart" , "Similar" , "One of the imaginary lines around the Earth" , "Imaginary line round the Earth" , "Running side-by-side but never meeting" .)
'port' is the definition.
(both can mean a place of safety)
This is all the clue.
(Other definitions for haven that I've seen before include "Harbour, oasis" , "Shelter (for ships)" , "Place of safety or sanctuary" , "Anchorage - retreat" , "Safe harbour" .)