[5.01/5.09] Definitions

Why do you think this is important at all?

In fact, for those who can spare the time, it is extremely instructive to read about the criteria for recognising new elements. Read, especially, section II.2 on the linked page. It is almost like a class in the Theory of Knowledge. Definitions are indeed somewhat arbitrary, while saving us from arbitrariness. This is the glorious paradox of definition.