Aching heart, or other part of one's person (4)
I believe the answer is:
chin
'other part of one's person' is the definition.
I can't judge whether this defines the answer.
'aching heart' is the wordplay.
'heart' means to look at the middle letters.
The centre of 'aching' is 'CHIN'.
'or' is the link.
Can you help me to learn more?
(Other definitions for chin that I've seen before include "Lower face part" , "part of mug" , "narrow opening" , "Possible double feature?" , "Feature of face" .)