The antonyms for the word "autonym" are "pseudonym," "alias," and "anonymous." A pseudonym is a fictitious name adopted by an author to conceal their identity, allowing them to write under a different persona. An alias is a false name or identity used by a person, often to avoid being identified. Anonymous refers to something that is without a name or identity, such as anonymous sources or anonymous donations. These antonyms are often used in contrast to autonym, which is a name given to oneself or one's work, as in the case of a writer or artist who uses their real name or a variation of it in their work.