Quick! What is the definition of the word moot? I'll use it in a sentence.
Upon reflection, Hezekiah realized that Ezekiel's argument was a moot point.
If you said something along the lines of "irrelevant", then you're wrong. Or perhaps, right. You see, moot is one of those strange words that can be self contradictory. Originally, moot started off as a noun. It was a legal term for a hypothetical case argued by law students. Sometime around the mid 16th century, it changed affiliations and became more commonly used as an adjective.
Thus, in my example above, Hezekiah believes in his heart that Ezekiel's argument is worthy of debate. However, around the 19th century, people started to use the word to mean "of no particular significance or relevance", which is the typical usage today. How confusing is that for the foreigner who looks up the word in the dictionary and finds both definitions? Context is everything. Perhaps we can submit the english language to ECMA for standardization.