Block on Trump's Asylum Ban Upheld by Supreme Court
While every lawyer may know what it means if a case or issue is given the old moot boot, consulting a dictionary could lead to some serious confusion. That's because the term "moot" derives from our ancestors across the pond and has a meaning in the UK which belies our American understanding.
Interestingly, in England, the term moot means "subject to debate, dispute, or uncertainty." Here in the U.S., where we speak English without an accent and have a much less colloquial lexicon, moot means "having little or no practical relevance." Given what it means when a case is rendered or ruled moot here in the U.S., the UK definition seems subject to some uncertainty of its own making.
An Irrelevant History
While we American lawyers recognize that a "moot point" is one that is not worth debating, it would seem that when the phrase was originally coined back in the 1500s, the English definition meant a point that was debatable. It originally derived from the old English word "mot" which meant an assembly or meeting, and the Germanic "motian" which meant "to converse."
As one etymology website explains, in medieval England, a "moot" was an assembly of individuals who would debate governmental issues. Notably though, after a point was discussed, that point would then be labeled as "mooted," as in, having been discussed by the "moot" group. Curiously, according to this British website, the term moot as we know it here in America came about thanks to moot courts.
However, as U.S. attorneys (should) know, the mootness doctrine has its humble roots in Article III of the Constitution. Article III requires a live case or controversy for a matter to be justiciable, and the doctrine of mootness stems directly from the lack of a controversy essentially preventing the court from taking meaningful action.