A more thorough explanation:

Aetate probanda is a Latin term used in law that means "of (about) proving age." It refers to a writ that orders the sheriff to summon a jury to determine whether an heir of a tenant holding an estate directly of the Crown was old enough to receive the estate.

One example of the use of aetate probanda is when a person inherits an estate from a tenant who held it directly from the Crown. In such cases, a writ may be issued to determine whether the heir is of legal age to receive the estate.

Another example is when a person claims to be of a certain age in order to receive a benefit or entitlement. In such cases, a court may order an aetate probanda to determine the person's true age.

These examples illustrate how aetate probanda is used to establish the age of a person in legal matters.