Moot

adjective

(British) Open to debate, argument, or confusion, usually without yielding a solution
(American) Irrelevant or unusable as a result of having no solution or clarity

verb

To bring up a topic for conversation or debate; propose

noun

A meeting or assembly of people to discuss or practice a common interest
(Law): A practice trial to prepare for or learn about a theoretical case (usually "moot court")

Usage

Despite its litany of definitions, moot today is most commonly used in the adjective form to describe a topic that is so completely murky or debatable as to be rendered useless for all practical purposes. It usually implies that there is some impasse about the topic that renders all discussion irrelevant (for example, the debate over which necklace to get your girlfriend would be moot if you can't afford any of them) or that there is some unknown aspect about a problem that gets in the way of finding a solution (for instance, the decision of what to have for dinner is moot if you don't know what your partner will have bought at the grocery store). Moot can also be applied to debates where each side's argument is valid enough to prevent any workable solution or decision from being reached. Often, the word is used to end a circuitous argument or conversation. It's a moot point - let's move on.

The less common verb form of moot describes the action of bringing up a topic or idea in a conversation. It often implies that one is making a suggestion or proposal in the midst of a difficult situation or argument. This form is commonly seen in the past-tense - e.g. "he mooted an idea".

If the verb form of moot is simply less common, the noun form is veritably obscure. Although the noun form does not have much of a place in daily conversation, it can be used to describe a congregation of like-minded people to discuss a shared interest or to discuss a topic relevant to all (think a meeting of Middle Eastern dignitaries to discuss oil exports, a Star Trek convention, or Entmoot - gathering of the Ents in The Lord of the Rings).

Historically, the original forms of moot were used to describe meetings and debates between community members or law professionals to discuss judiciary affairs. Today, the word retains something of this initial meaning, as the phrase moot court is sometimes used in law to describe a practice trial session involving a theoretical case that is used as a learning or academic experience.

Example: The decision about what to watch on television that night was rendered moot when the power went out.

Example: After half an hour of fruitless wandering, Curly mooted the idea that the group stop to ask for directions.

Origin

The earliest origins of moot were in the noun form, despite that being the least common usage today. Initially formed from a Proto-Germanic term, the word entered Old English in the twelfth century in the form of gemot, which referred to a council of community members who came together to discuss issues and make judicial decisions. Eventually, mōt developed as a general word to describe a meeting or convention. Moot took on its adjective form in the sixteenth century as an expression in law to refer to something that was debatable or up for discussion; specifically, it became used in the phrase moot court to describe hypothetical court cases staged for practice. From both of these usages, the verb form developed to describe the action of debating.

Derivative Words

Moots: The third-person present tense form of moot is used when a singular subject brings up a topic for discussion.

Example: The students' hopes are always raised when Jimmy moots the prospect of having class outside.

Mooting: This form is used to describe when someone is currently broaching a topic, or as a noun to refer to the action of bringing something up in conversation.

Example: It only took until the second week of April that Mrs. Pennyfeather grew sick of Jimmy's constant mooting that the class go outside.

Mooted: This is the preterit form of the verb moot.

Example: Mrs. Pennyfeather swore to herself that if Jimmy mooted the idea one more time, she would lock him outside the classroom.

In Literature

From Herman Melville's Moby-Dick:

The uncertain, unsettled condition of this science of Cetology is in the very vestibule attested by the fact, that in some quarters it still remains a moot point whether a whale be a fish.

Here, Melville is musing over how little was known about the study of whales at the time he was writing, evidenced by the fact that many people were unsure, i.e. open to debate, whether or not a whale was a fish. Even today, a number of people remain unaware that a whale is a mammal.

From The Economist, The Paperless Dilemma (Sept 29, 2014):

Ever since the "paperless office" was first mooted in a Business Week article back in 1975, its estimated time of arrival has always been ten years away.

Here mooted is used to convey the proposal of an idea - that of the ever elusive paperless office.

Mnemonic

If discussion can't take root, the point is moot.
A lawyer's moot is a practice lawsuit.