This word is commonly used by fans of the best-selling book series, Harry Potter. Riddikulus is the spell used to transform a boggart into something less fear-inducing. Professor R.J. Lupin taught this incantation to Harry Potter and his classmates in Defense Against the Dark Arts during their 3rd year at Hogwarts School of Witchcraft and Wizardry.
Cool person 1: Are you sirius? That's riddikulus! It's impossible not to be drawn to the plot!
Person 1: Did you see Ron Weasley's dress robes at the Yule Ball?
Person 2: Yeah. He must've felt riddikulus.