Foreshowing; indicating something in the future by signs or symptoms: as, the prognostic indications of a disease.n. That which prognosticates or foretells; a sign by which a future event may be known or foreshown; an omen; a token.n. A prediction; a foretelling.n. Synonyms Sign, Presage, etc. See omen, and foretell, v. i.To prognosticate.