Tenfold is an adjective and an adverb meaning ten times greater or 10 times bigger. This is an expression you might hear more in formal contexts.

1. The country's economy has grown tenfold since the peace agreement was signed, ending a costly five-year war with their neighbours.
2. Our bills have gone up tenfold since we moved to the city and had two children.

1. At the AGM this evening, the Board are expected to announce a tenfold increase in the company's profits compared to last year. It has been quite a turnaround!
2. Brian persuaded investors that if they each put a small sum of money into his business, he would pay them back tenfold within five years. The whole thing turned out to be a swindle.