Course right for passenger ship (5)
I believe the answer is:
liner
'for passenger ship' is the definition.
(eg a cruise liner)
'course right' is the wordplay.
'course' becomes 'line' (synonyms).
'right' becomes 'r' (abbreviation).
'line'+'r'='LINER'
(Other definitions for liner that I've seen before include "Big ship" , "Passenger transport" , "Passenger ship - bin bag" , "Large passenger vessel" , "Large ship or removable layer of material" .)