Something or someone that causes great suffering or a lot of trouble: (Cambridge Dictionary)
Whip, especially one used to inflict pain or punishment. (Merriam – Webster)
An instrument of punishment or criticism. (Merriam – Webster)
A cause of wide or great affliction. (Merriam – Webster)
A whip used as an instrument of punishment. (Oxford Dictionaries)
A person or thing that causes great trouble or suffering. (Oxford Dictionaries)
A scourge is something that causes a lot of trouble or suffering to a group of people. (Collins Dictionary)
If something scourges a place or group of people, it causes great pain and suffering to people. (Collins Dictionary)
The Roman scourge enlarged.
The original meaning of “Scourge” and how it changed.