Under-write is a financial term used to describe the process of guaranteeing a certain sum of money in case a particular event occurs. Some common antonyms for the term under-write include words like deny, refuse, reject, or decline. These words are often used in the context of insurance policies or loan applications where the applicant may be considered too risky to offer coverage or financing. Other antonyms for under-write might include words like disavow, neglect, or abandon, which describe a complete lack of support or backing for a particular venture or initiative. Ultimately, the antonyms for under-write focus on the idea of not providing support or backing in different ways.