verb
underwrite
un-der-RYTE/ˌʌndərˈraɪt/
To assume financial responsibility for supporting an undertaking.
The provider underwrites the housing undertaking by guaranteeing financial support.

Etymology
Writing beneath an agreement meant signing it. Signing a marine insurance policy committed the signer to cover specified losses, so underwrite came to mean accepting financial risk or providing a money guarantee.
In context
less willing or able to underwrite the kinds of huge long-term investments
More examples
- A foundation underwrote the museum's new exhibition.
- The insurer underwrites policies for small businesses.
- The festival cannot proceed without someone underwriting its costs.
Forms
underwrite · underwrites · underwrote · underwritten · underwriting
underwriter noun — A person or company assuming financial risk.