Row to the royal ship (5)
I believe the answer is:
liner
'ship' is the definition.
(liner is a kind of ship)
'row to the royal' is the wordplay.
'row' becomes 'line' (I've seen this before**).
'to the royal' becomes 'r' (abbreviation).
'line'+'r'='LINER'
(Other definitions for liner that I've seen before include "that's put in bin" , "cover for interior" , "boat" , "Large passenger or cargo ship travelling on regular route" , "Large ship or removable layer of material" .)