a banker who deals chiefly in underwriting new securities
"The investment bank's lead underwriter took responsibility for selling millions of dollars worth of new government bonds to institutional investors."
an agent who sells insurance
"The new underwriter reviewed my application and approved coverage for my home immediately."
a financial institution that sells insurance
"The local bank acted as the underwriter for our new business policy last year."
An entity assuming a financial risk.
"The insurance company acted as an underwriter by agreeing to assume the full financial risk if the factory burned down next week."