The phrase "single lump" refers to a situation when something is combined or bundled into one big piece instead of being divided into smaller parts. Full definition
With a single premium deferred annuity, just one single lump sum payment is needed to attain a guaranteed stream of income in retirement. (goodfinancialcents.com)
A single premium immediate annuity is an annuity offered by insurance companies that requires one single lump sum payment in order to receive the benefit of regular payments for a certain amount of time. (insuranceopedia.com)
In case of death during the policy term and that the policy is in force the sum assured will be paid to the nominee as single lump sum (coverfox.com)