The phrase "minimum guarantee" refers to the lowest level of something that is promised or ensured. It means that no matter what happens, there is a specific minimum amount or condition that will be provided or maintained. Full definition
The proceeds after addition of interest subject to minimum guaranteed interest rate is payable after the end of the lock - in period. (comparepolicy.com)
When pressed about this confusion, universal life insurance companies point to the disclosed minimum guaranteed rate. (jrcinsurancegroup.com)