Hearsay about bit of corn (3)
I believe the answer is:
ear
'bit of corn' is the definition.
('ear' is part of 'corn')
'hearsay about' is the wordplay.
'about' says the answer is hidden in the clue.
'EAR' can be found hidden inside 'hearsay'.
(Other definitions for ear that I've seen before include "Organ of hearing" , "See 8" , "Sense organ" , "Go astray" , "organ with drum" .)