Figure who may inflame aching back (4)
I believe the answer is:
eros
'figure who may inflame' is the definition.
(Greek god of love who may inflame passion)
'aching back' is the wordplay.
'aching' becomes 'sore' (I've seen this before).
'back' is a reversal indicator.
'sore' written backwards gives 'EROS'.
(Other definitions for eros that I've seen before include "Group of instincts" , "Arrow-shooting god" , "Cupid, son of Aphrodite" , "Name given to statue" , "divinity" .)