Generally: To accrue to; to be fixed; to take effect; to give a fixed and Indefeasible right. This may include the vesting of stock options as part of an employment agreement after a stated number of years of servitude by an employee. estates. To give an immediate fixed right of present or future enjoyment; an estate is vested in possession when there exists a right of present enjoyment; and an estate is vested in interest, when there is a present fixed right of future, enjoyment. An estate is vested in possession when there exists a right of present enjoyment; and an estate is vested in interest when there is a present fixed right of future enjoyment Fearne, Rem. 2. To clothe with possession; to deliver full possession of land or of an estate; to give seisin; to enfeoff.