To assume financial responsibility for a project, typically by providing a guarantee against loss. The bank agreed to underwrite the new housing development, ensuring its financial stability.
To sign and accept liability under an insurance policy, thus guaranteeing payment in case of loss or damage. The insurance company will underwrite the policy for the new car, covering any potential accidents.
To support or sponsor an event, activity, or publication financially. The corporation decided to underwrite the charity concert, covering all the associated costs.
(Archaic) To write one’s name at the end of a document or text; to sign beneath. The clerk underwrote the charter with an elegant flourish.