Draw a boat (3)
I believe the answer is:
I believe this is a double definition.
'draw' is the first definition.
(I know that tug is a kind of draw)
'a boat' is the second definition.
(I know that tug is a type of boat)
(Other definitions for tug that I've seen before include "Pull forcibly" , "Pull hard; boat" , "Pull sharply" , "Pull vigorously, yank" , "Sudden abrupt pull" .)