<p><strong>Verb</strong></p><ul><li>(used with object) to write under or at the foot of, especially under other written matter.</li><li>to sign one's name, as to a document.</li><li>to show agreement with or to support by or as if by signing one's name to, as a statement or decision.</li><li>to bind oneself to contribute a sum of money to (an undertaking): Wealthy music lovers underwrote the experimental concerts.</li><li>to guarantee the sale of (a security issue to be offered to the public for subscription).</li><li>Insurance: to write one's name at the end of (a policy), thereby becoming liable in case of certain losses specified in the policy.</li><li>to insure.</li><li>to assume liability to the extent of (a specified sum) by way of insurance.</li><li>to select or rate (risks) for insurance.</li></ul><p><strong>Verb</strong></p><ul><li>(used without object) to underwrite something.</li><li>to carry on the business of an underwriter.</li></ul>