Two-masted sailing boat (4)
I believe the answer is:
yawl
'two-masted sailing boat' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for yawl that I've seen before include "Two-masted sailing vessel" , "Sailing-ship" , "Two-masted sailing boat" , "Ships small boat" , "A two-master" .)