Okay, so you know how people have words for things? Like "dog" for that furry friend you like to play with, or "cake" for that yummy dessert you love to eat? Well, a long time ago, people had a word for a type of magic that they did. They called it "wicca."
But where did that word come from? Well, it's kind of like a grown-up game of telephone. A really, REALLY long time ago, the people who spoke a language called Old English had a word that sounded like "wicca." It meant someone who did magic.
Over time, the word changed a bit. People in different parts of England said it differently, and spelled it differently. By the time you get to the 1900s, some people in England and America wanted to start a new religion that used magic. They decided to call it Wicca, because that's what their ancestors had called people who did magic.
So that's where the word "Wicca" comes from! It's an old word that meant magic, and people who started a new religion liked the sound of it, so they used it to name their religion.