Course right for ship (5)
I believe the answer is:
liner
'for ship' is the definition.
(as in an ocean liner)
'course right' is the wordplay.
'course' becomes 'line' (synonyms).
'right' becomes 'r' (common abbreviation).
'line'+'r'='LINER'
(Other definitions for liner that I've seen before include "Big ship" , "Pleasure cruiser" , "Seagoing vessel - goes with bin, eye or hard" , "Commercial ship" , "LP's inner sleeve" .)