Look after harbour (5)
I believe the answer is:
nurse
This clue is a double definition.
'look after' is the first definition.
(thesaurus)
'harbour' is the second definition.
(I've seen this before)
(Other definitions for nurse that I've seen before include "Medical worker" , "Child minder" , "One ministering to the sick" , "Hospital employee" , "Carer for the sick; shark" .)