A more thorough explanation:

Ademptio

Ademptio is a legal term from ancient Rome that means "ademption." It refers to the cancellation of a bequest or legacy under certain circumstances. For example, if the item that was bequeathed no longer exists or if the testator no longer owns the item, the bequest is cancelled. The term ademptione means "by ademption."

Suppose a person writes a will and leaves their car to their nephew. However, before the person dies, they sell the car. In this case, the bequest of the car is cancelled by ademption because the car no longer exists.

Another example is if a person leaves their house to their daughter, but then they sell the house and move into an apartment. The bequest of the house is cancelled by ademption because the testator no longer owns the house.