Part of body needing listener to be in shape (7)
I believe the answer is:
forearm
'part of body' is the definition.
(I've seen this before)
'listener to be in shape' is the wordplay.
'listener' becomes 'ear' (I've seen this before).
'to be in' means one lot of letters goes inside another.
'shape' becomes 'form' (synonyms).
'ear' placed within 'form' is 'FOREARM'.
'needing' acts as a link.
(Other definitions for forearm that I've seen before include "Limb part; prepare" , "Before battle, take up weapon" , "Prepare to defend" , "where is the radius?" , "what's near to hand?" .)