Predictor (noun)

1. A person or thing that predicts, or makes a forecast or prediction.
2. A variable that can be used to predict the value of another variable.

Origin:

From latin praedictor ("foreteller"), from praedicere ("to foretell"), from prae ("before") + dicere ("to sa.y")

Examples:

1. He is a weather predictor for the local news.
2. The stock market predictor predicted a rise in stock prices.
3. The predictor variable in this study is age.
4. The predictor tool uses machine learning to forecast sales.
5. The predictor model was able to accurately predict the outcome of the election.