Like a bird behind a boat (6)
I believe the answer is:
astern
'like a bird behind a boat' is the definition.
I can't judge whether this definition defines the answer.
'like a bird behind' is the wordplay.
'like' becomes 'as'.
'a bird' becomes 'tern' (tern is a kind of bird).
'behind' means one lot of letters go next to another.
'as'+'tern'='ASTERN'
Can you help me to learn more?
(Other definitions for astern that I've seen before include "Aft" , "Behind (naut.)" , "Behind the back of a ship" , "Behind at sea" , "Backward" .)