Today I found a term I like based off of an old quote; the Rumsfeld unknown. A Rumsfeld unknown is a outcome or circumstance which cannot be predicted by an observer. Previously referred to as an unknown unknown.

There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we now know we don’t know. But there are also unknown unknowns. These are things we do not know we don’t know.

- Donald Rumsfeld