Godwin's law

Etymology
.

Proper noun

 * 1)  The adage that any Usenet discussion will eventually mention the Nazis or.
 * 2)  An adage that states that the first person in an argument (usually in an online comment thread or forum) to mention the Nazis or  has lost.
 * 1)  An adage that states that the first person in an argument (usually in an online comment thread or forum) to mention the Nazis or  has lost.
 * 1)  An adage that states that the first person in an argument (usually in an online comment thread or forum) to mention the Nazis or  has lost.

Usage notes

 * Mentioning Godwin's law as having been fulfilled in a particular discussion is often deemed sufficient grounds for ending that discussion.