A Halloween costume is an outfit worn during the celebration of Halloween, which takes place on October 31st each year. People of all ages dress up in various costumes, often inspired by monsters, superheroes, or popular characters from movies and books. The tradition of wearing costumes dates back to ancient times when people believed that disguising themselves would ward off evil spirits. Costumes can be homemade or purchased from stores, and they often include accessories like masks, hats, and props. Many people enjoy attending Halloween parties or going trick-or-treating while wearing their costumes, making it a fun and festive part of the holiday.