What does beneficiary mean?

A beneficiary means one who benefits from something. The benefit may come from an estate, trust, annuity, insurance policy or some similar source.
Where there is a will there is a relative. Let us say a rich Uncle likes one of his relatives he will make out his will so that when the Uncle dies the relative he likes will get his money and benefit by it. Thereby that relative becomes a "BENEFCIARY" (Beneficiary)