Bird takes fruit endlessly — there’s remorse about that (9)
I believe the answer is:
guillemot
'bird' is the definition.
(guillemot is a kind of bird)
'fruit endlessly there's remorse about that' is the wordplay.
'fruit' becomes 'lemon' (lemon is a kind of fruit).
'endlessly' means to remove the last letter.
'there's remorse' becomes 'guilt' (I can't justify this - if you can you should give a lot more credence to this answer).
'about that' is an insertion indicator.
'lemon' with its final letter removed is 'lemo'.
'lemo' going inside 'guilt' is 'GUILLEMOT'.
'takes' acts as a link.
Can you help me to learn more?
(Other definitions for guillemot that I've seen before include "Seabird" , "cliff-ledge nester" , "An auk" , "Diver" , "Diving bird" .)