When you rollick, you have a fabulously fun time. You probably won't rollick during quiet reading time at school, but you'll have a chance to rollick at your best friend's roller disco party.
People rollick during parties and dances, while they play active games, and even when they're watching hilariously funny movies. You can also say cavort, revel, or frolic—and experts guess that rollick comes from a combination of the words frolic and roll. The adjective rollicking is more common than the verb, and predates it by about 15 years.