Entry 1 sense Webster, 1913 Prognosticator · Prog·nos·ti·ca·tor · IPA /pɹɒɡˈnɒstɪkeɪtə(ɹ)/ 01 n. One who prognosticates; a foreknower or foreteller of a future course or event by present signs. 1. One who prognosticates; a foreknower or foreteller of a future course or event by present signs.