One often landed with large bill (7)
I believe the answer is:
pelican
'bill' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Maybe there's a link between them I don't understand?
'one often landed with large' is the wordplay.
I cannot quite see how this works, but
'one' could be 'an' (an apple is one apple) and 'an' is found within the answer.
'large' could be 'l' (eg in clothes sizes) and 'l' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for pelican that I've seen before include "Seabird having a large bill with a pouch for fish" , "The large bird is in place" , "one with huge bill" , "Its beak holds more than its belly can" , "Aquatic, billed bird" .)