Risk and Uncertainty
A probability or threat of damage, injury liability, loss, or any other negative occurrence that is caused by external or internal vulnerabilities, and that may be avoided through pre-emptive action. A risk is not an uncertainty.
It is where neither the probability nor the mode of occurrence is known. It is unknown unknowns according to Donald Rumsfed.
It is defined as unknown knowns according to Donald Rumsfed. We know but we choose to unknow them.