Pulp eaten by bird, sticky thing (8)
I believe the answer is:
flypaper
'bird sticky thing' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'pulp eaten by' is the wordplay.
'pulp' becomes 'pap' (both can mean worthless or trivial stuff).
'eaten' indicates putting letters inside.
'by' becomes 'flyer' (I can't explain this - if you can you should give a lot more credence to this answer).
'pap' going within 'flyer' is 'FLYPAPER'.
Can you help me to learn more?
(Other definitions for flypaper that I've seen before include "Sticky stuff to trap insects" , "Killer" , "Sticky insect trap" , "for hanging being used for killing" , "should stick to the buzzer" .)