Whip a person who causes great suffering (7)
I believe the answer is:
scourge
'whip' is the definition.
(scourge is a kind of whip)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for scourge that I've seen before include "Flagellate" , "menace" , "Cause great suffering to (someone); whip" , "Flog, punish" , "form of punishment" .)