noun: (Internet, usually humorous) The adage that any Usenet discussion will eventually mention the Nazis or Adolf Hitler.
noun: (usually humorous) An adage that states that the first person in an argument (usually in an online comment thread or forum) to mention the Nazis or Adolf Hitler has lost.
noun: Alternative form of Godwin's law [(Internet, usually humorous) The adage that any Usenet discussion will eventually mention the Nazis or Adolf Hitler.]