forecastforecastforecasts1nounwhat somebody thinks will happen, based on the information that is available: The weather forecast said that it would rain today.forecastforecastforecastsforecastedforecasting2verb (forecasts, forecasting, forecast, has forecast)to say what you think will happen, based on the information that is availablesame meaningpredict: They've forecast rain.▶ forecasterforecasterforecastersnoun: She's a weather forecaster on TV.