Part of body originally protecting ‘the King’? (6)
I believe the answer is:
pelvis
'part of body' is the definition.
(the pelvis is a body part)
'originally protecting 'the king'?' is the wordplay.
'originally' suggests taking the first letters.
''the king'?' becomes 'elvis' (I've seen this before).
The first letter of 'protecting' is 'p'.
'p'+'elvis'='PELVIS'
(Other definitions for pelvis that I've seen before include "Basin-shaped framework of bones at lower end of body" , "Part of body" , "Large part of skeleton" , "Large bony frame" , "Bony structure at the base of the spine" .)