Hold course for port! (5)
I believe the answer is:
haven
'for port' is the definition.
(both can mean a place of safety)
'hold course' is the wordplay.
'hold' becomes 'have' (synonyms).
'course' becomes 'n' ().
'have'+'n'='HAVEN'
(Other definitions for haven that I've seen before include "A peaceful refuge" , "Harbour - shelter" , "relaxing place" , "Shelter (for ships)" , "Safe harbour" .)