Trimmer sailing vessel that goes quickly (7)
I believe the answer is:
clipper
This clue is a double definition.
'trimmer' is the first definition.
(device which trims or clips)
'sailing vessel that goes quickly' is the second definition.
(speedy type of ship)
(Other definitions for clipper that I've seen before include "used to dock" , "Ticket inspector" , "boat" , "Old ship" , "under sail" .)