Monstrous woman to advance, shunning PR (6)
I believe the answer is:
ogress
'monstrous woman' is the definition.
(female ogre)
'advance shunning pr' is the wordplay.
'advance' becomes 'progress' (to progress is to advance).
'shunning' suggests deleting specific letters.
'progress' with 'pr' taken out is 'OGRESS'.
'to' is the link.
(Other definitions for ogress that I've seen before include "Terrifying female" , "Giant woman" , "Man-eating giantess" , "Female giant of fairy tales" , "Female monster" .)