moot

before 900; Middle English mot( e) meeting, assembly, Old English gemōt; cognate with Old Norse mōt, Dutch gemoet meeting. See meet¹

The modern noun moot comes from the Old English mōt “meeting, court,” typically used in compounds such as gemōt “(legislative or judicial) assembly, council,” folcmōt, folcgemōt “popular assembly (of a town or shire),” and witena gemōt “assembly of wise men.” Nouns in other Germanic languages related to mōt include Old Saxon mōt (Old Saxon was the earliest recorded form of Low German; it was spoken in northern Germany, the northeastern Netherlands, and southern Denmark) and Middle High German muoz. All of these nouns derive from Germanic mōta-, from which was derived the verb mōtjan, which becomes mōtian in Old Saxon, mētan and moeta in Old English, and meet in modern English.
In 16th-century England, a moot was “a hypothetical case or point for law students to practice on.” This is where we get the terms moot point and moot court. Moot later developed the sense “open to discussion, debatable, doubtful,” and finally “impossible to be settled.” In American legal usage in the first half of the 19th century, moot developed an additional sense “having no effect, purely academic, abstract” (now used only outside legal contexts), but American usage also retained the original sense “remaining open for debate or consideration,” leaving the meaning of moot point in conversation up for grabs: Is it a debatable point, or irrelevant?