prognosticatory UK /pɹɒɡˈnɒstɪkətəɹi/US /pɹɑɡˈnɑstɪkətɔɹi/ adjective1 •That prognosticates or makes predictions about the future; predictive.Most of the almanac-makers had gone over to Copernicanism by this time, but it made no difference to their prognosticatory activities. — 1971 formsmore prognosticatory · most prognosticatory