A more thorough explanation:

Per autre vie is a legal term that means "for another's life." It is a Law French term that refers to a period of time that is measured by the life of someone other than the person who holds the property or estate.

An example of per autre vie would be if a person owned a piece of property and granted someone else the right to use it for the duration of their spouse's life. In this case, the property would be held per autre vie of the spouse.

Another example would be if a person granted a life estate to their child, but the duration of the estate was measured by the life of the child's spouse. In this case, the estate would be held per autre vie of the spouse.

The examples illustrate the definition of per autre vie by showing how the duration of a property or estate can be measured by the life of someone other than the person who holds it. This legal term is often used in situations where a person wants to grant someone else the right to use their property or estate for a certain period of time, but that period of time is tied to the life of another person.