Flier with a big bill for fish (7)
I believe the answer is:
pelican
'flier' is the definition.
(pelican is a kind of birdanimal)
'a big bill for fish' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'an' and 'an' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'with' is the link.
Can you help me to learn more?
(Other definitions for pelican that I've seen before include "Large bird with enormous beak" , "In place (anag.)" , "Seabird having a large bill with a pouch for fish" , "Water bird with throat pouch for fish" , "Its beak holds more than its belly can" .)