mutability

noun

1. (countable, uncountable)The quality or state of being mutable.

   “He did indeed account somewhat unfairly for this sudden change; for besides some hard and unjust surmises concerning female fickleness and mutability, he began to suspect that he owed this want of civility to his want of horses […]”

   “There rise authors now and then, who seem proof against the mutability of language, because they have rooted themselves in the unchanging principles of human nature.”