The phrase "post factum" is a Latin term that refers to something that has happened or taken place after a particular event or circumstance. Some synonyms for this phrase include "after the fact," "retrospectively," "in hindsight," and "subsequently." These terms all convey a sense of something being done or considered after the initial event has occurred. Other related phrases include "in the aftermath," "in the wake," and "in the aftermath of the event." No matter which term or phrase is used, they all convey the idea of reflecting on something that has already passed and perhaps reconsidering or revising previous thoughts or actions based on new information or understanding.