What’s the Tie-In to the Harry Potter Wizengamot?
"Moot" is the root of "gemote," which meant "assembly." Remember that “moot” was originally a noun that described a group or an assembly, so it makes sense that “moot” and “gemote’ are related. "Gemote" is, in turn, one of the roots of the word "Witangemot."
The Wizengamot Shares the Same Root as “Moot”
The Witangemot was a national Anglo-Saxon body that advised the kings. It was something like a modern parliament or legislative body. In the Harry Potter books, the body that acts like the high court for the wizarding world is called the Wizengamot and it's modeled after the Witangemot. So the word “moot” is related to the name of that wizard high court.
Law Students Argue in Moot Court
A "moot" was originally a group of lawyers or politicians, and they used items called "moot horns" or "moot bells" to call the assemblies together.
Later, in the 16th century, "moot" started to refer to a group of lawyers or students arguing hypothetical cases. For example, you may have heard of law students participating in something called moot court. When students started doing that, the noun "moot" also started to mean “an argument.” It's actually used on the title page of the Magna Carta. It reads: With an Almanac and Calendar to know the moots, necessary for all young studiers of the law.
In Britain, “Moot” Can Still Mean “Debatable”
In the 16th century, “moot” also took on a meaning as an adjective that meant an arguable or debatable point, and it still holds on to that meaning in Britain.
In America, “Moot” Means “Pointless”
But in America, the idea of students going through the academic exercise of trying hypothetical cases led to "moot" taking on the meaning of something that doesn't matter. That's its main meaning in America, but if you're writing for an international audience, you should be aware that it can also mean a point that is arguable or debatable, so be sure to make your meaning clear. And remember, whether you mean that something is arguable or pointless, the spelling is m-o-o-t.