Captain who's drawn from harbour by drunk (7)
I believe the answer is:
haddock
'captain who's drawn' is the definition.
(Captain Haddock in Tintin comics)
'harbour by drunk' is the wordplay.
'harbour' becomes 'dock' (I've seen this before).
'by' says to put letters next to each other.
'drunk' becomes 'had' (I can't justify this - if you can you should believe this answer much more).
'dock' put after 'had' is 'HADDOCK'.
'from' acts as a link.
Can you help me to learn more?
(Other definitions for haddock that I've seen before include "Fish like cod but smaller" , "Edible fish like small cod" , "White fish" , "Fish similar to but smaller than cod" , "ish" .)