The word "under wrote" is often used in finance or insurance industries to describe when a company provides less coverage or protection than what is typically offered. Some potential antonyms for "under wrote" could include "over wrote", which would indicate that a company provided too much coverage or protection, or "fully wrote", which would suggest that a company provided the standard or expected amount of coverage. Other antonyms could include "abundantly wrote", "generously wrote", or "comprehensively wrote", all of which would indicate that the company went above and beyond in providing coverage or protection. The choice of antonym would depend on the context and desired emphasis of the situation.