Being out of place in harbour, finally sailor returned (6)
I believe the answer is:
stupor
'being out' is the definition.
(being almost unconscious or 'out of it')
'place in harbour finally sailor returned' is the wordplay.
'place' becomes 'put' (synonyms).
'in' means one lot of letters goes inside another.
'finally' says to take the final letters.
'sailor' becomes 'os' (ordinary seaman).
'returned' says the letters should be written backwards.
The final letter of 'harbour' is 'r'.
'r'+'os'='ros'
'put' put into 'ros' is 'roputs'.
'roputs' written backwards gives 'STUPOR'.
'of' is the link.
(Other definitions for stupor that I've seen before include "numbness" , "State of being stunned" , "Insensible state" , "State of near insensibility" , "State of being dazed or numb" .)