Knock the boat (5)
I believe the answer is:
barge
This clue might be a double definition.
'knock' is the first definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'boat' is the second definition.
(I know that barge is a type of boat)
'the' is the link.
Can you help me to learn more?
(Other definitions for barge that I've seen before include "Roughly push one's way" , "River transport" , "Shove - canal boat" , "Push - boat" , "Long, flat-bottomed boat" .)