Bird shown as 'duck' in list (7)
I believe the answer is:
rooster
'bird' is the definition.
(rooster is a kind of bird)
'duck in list' is the wordplay.
I cannot quite see how this works, but
'duck' could be 'o' and 'o' is found within the answer.
'list' could be 'roster' (roster is a kind of list) and 'roster' is present in the remaining letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
'shown as' is the link.
(Other definitions for rooster that I've seen before include "Crowing bird" , "Cockerel (mainly US)" , "One may crow" , "So retro (anag.)" , "Morning caller" .)