Used in medical and general contexts to mean a sign or indicator that foretells an outcome.
Definitions
A sign, symptom, or other piece of evidence that foretells or indicates the probable course or outcome of something, especially of a disease. Severe chest pain is often regarded as a poor prognostic sign for long-term survival after a heart attack.
An act or instance of predicting; a forecast or prognostication. His gloomy prognostic of the company's future proved inaccurate.