Cruel person helping to make progress (4)
I believe the answer is:
ogre
'cruel person' is the definition.
(I've seen this in another clue)
'helping to make progress' is the wordplay.
'helping to make' says the answer is hidden in the clue.
'OGRE' can be found hidden inside 'progress'.
(Other definitions for ogre that I've seen before include "Fierce giant" , "Terrifying giant" , "Cruel giant of folklore" , "Human-eating giant" , "Giant who eats people" .)