Paper heart, perhaps (5)
I believe the answer is:
organ
This clue is a double definition.
'paper' is the first definition.
(thesaurus)
'heart perhaps' is the second definition.
(heart is a kind of organ)
(Other definitions for organ that I've seen before include "Biological functionary" , "Ear, perhaps" , "Mouthpiece" , "Perhaps one that's stopped" , "Soft part of the body which has a specific function" .)