The word 非常 is formed through a conceptual fusion of its two constituent characters: 非, which carries the fundamental meaning of "not" or "to be contrary to", and 常, which means "constant", "ordinary", or "usual". When combined, they create a literal, ideographic concept of "not usual" or "not ordinary". This core idea of stepping outside the realm of the normal or regular naturally evolved to express a heightened degree, thereby forming an adverb that means "very" or "extremely", as something that is "not ordinary" is, by definition, exceptional or intense.