Ports (7)
'ports' is the definition.
(harbour is a kind of port)
This is the entire clue.
(Other definitions for harbours that I've seen before include "Bar hours in refuges" , "Provides asylum for, as for ships" , "Sheltered ports" , "Shelters in ports" .)
'ports' is the definition.
(harbor is a kind of port)
This is all the clue.