Hearsay includes listener (3)
I believe the answer is:
ear
'listener' is the definition.
(body part which hears or listens)
'hearsay includes' is the wordplay.
'includes' says the answer is hidden in the clue.
'EAR' is hidden in the letters of 'hearsay'.
(Other definitions for ear that I've seen before include "Hammer in this" , "Lend one and listen" , "Shell-like; corn" , "cut" , "Seed-bearing part of wheat" .)