an entertainer who wears funny clothes, has a painted face, and makes people laugh by performing tricks and behaving in a silly way

someone who behaves in a silly way, often intentionally

to act stupidly, often to make other people laugh

Left alone, the class threw books, pulled faces, and generally clowned around. 由于没有人管，班上的学生扔书本，扮鬼脸，简直胡闹成一片。