Spreading in debate is when someone talks very fast to say as much as they can in a short amount of time. It's kind of like when your mom or dad gets really excited and starts talking really fast, but instead of talking about fun things like toys or games, people who spread talk about important things like ideas and arguments.
People spread in debate because they want to fit as many ideas as they can into the time they are given to speak. It's kind of like trying to fit as much ice cream as you can into a small cup - you want to make the most of the time you have.
But sometimes when people spread, it can be hard to understand what they're saying because they're talking so fast. It's like when you're listening to a song and the singer is singing really fast, and you can't quite catch all the words.
So, while spreading can be helpful in getting a lot of ideas across, it's important to remember that it's also important to speak clearly and not overwhelm the people you're trying to convince.