›FINANCEto give an activity financial support and take responsibility for paying any costs if it fails: He underwrote a friend's development company in New York.Many businesses have underwritten the event.
›INSURANCEif a company underwrites an insurance policy or someone's property, it agrees to pay out money in cases of damage, loss, etc.: Why should insurance companies underwrite policies for people moving into areas that have a high probability of wildfires?
›STOCK MARKETif a financial organization underwrites new shares when they are offered for sale, it agrees to buy any shares that are not sold: The firm underwrote $12 billion of securities last year.The rights issue is fully underwritten.