A long time ago, there were no dictionaries, no modern language associations, no Oxford standards. Language is a fundamentally organic system that has been evolving for thousands of years, as complex and intricate as something like the economy, and for most of its existence its rules have not been explicit.
Word Creation
Some people might decry this as unnecessary complexity, and in some cases the variability and mutability of language can be a disadvantage. Certainly in science and engineering, it is necessary to be very, very careful and precise with language in order to communicate your meaning, and there are some meanings that cannot be adequately communicated with our language at all, as we don't have the words; it's one of the hazards of trying to talk about the nature of reality using a communication technique developed to tell people where the best fruit is.
IGC Publishing 