Tasteless cake rejected by papers (5)
I believe the answer is:
vapid
'tasteless' is the definition.
(I've seen this in another clue)
'cake rejected by papers' is the wordplay.
I cannot really understand how this works, but
'papers' could be 'id' (identification papers) and 'id' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for vapid that I've seen before include "Offering no stimulation" , "Dull, insipid, flat" , "Wishy-washy" , "Lacking flavour" , "Insipid - lacking significance" .)