Fourfold (adjective)

1. Four times as great or as many.
2. Four times as much in amount or degree; multiplied by four.

Origin:

From four (number) + -fold (suffix) meaning four times as great or as many.

Examples:

1. The profit increased fourfold.
2. The population has grown fourfold in the last decade.
3. The intensity of the storm increased fourfold.
4. The price of the stock has gone up fourfold.
5. The number of tourists has increased fourfold in the past year.