Examples of 'A posterior' knowledge
The terms "a priori" and "a posteriori" are used among philosophers to refer to two different types of knowledge. A posteriori knowledge is wisdom that we can have only after we have certain experiences. Whereas 'A priori' knowledge is wisdom that we can have "prior to experience".
A posteriori fact is concluded through a posteriori reasoning that involves facts observed in the world. For example, the fact that Anne has blonde hair would be an a posteriori truth, based on a posteriori reasoning. However, like all a posteriori knowledge, this statement could be false. With hindsight you could learn that her hair was dyed.