A knout is a type of whip that was used a long time ago. It's made of lots of long, thin pieces of leather that are tied together at the end, and it's really, really long.
Knouts were used to punish people in some countries. When someone did something wrong, they would be tied up and someone would use the knout to hit them. It would hurt a lot because the pieces of leather would hit their skin really hard.
Knouts were really scary and people were very afraid of them. It was a really cruel way to punish someone, and thankfully, it's not used anymore.