The term 'believer in nothing' is often used to describe a NIHILIST, which is an 8-letter word. A NIHILIST is someone who believes that life is meaningless and that nothing has any real value or purpose. They reject all religious and moral principles, as well as the belief that life has any inherent meaning. Nihilists often view the world as a chaotic and unpredictable place, and they may even deny the existence of objective truth.