Pervasiveness is the noun for the fact — or the degree — of being everywhere: how widely something has spread. You talk about the pervasiveness of a problem, a habit, or a smell when you want to name the spread itself, not just call the thing pervasive. It is a formal word, more at home in writing and serious talk than in everyday chat. Like pervasive, it often points to something people worry about, though it does not have to.

普遍性、瀰漫的程度