A more thorough explanation:

Definition: Liferent is a legal term used in Scots law that refers to the right to use and enjoy someone else's property (known as the fiar) during one's lifetime without consuming its substance. It is similar to the concept of usufruct in Roman and civil law, which is the right to use and enjoy the fruits of another's property for a period without damaging or diminishing it, although the property might naturally deteriorate over time.

For example, if John owns a house and grants Mary a liferent, Mary has the right to use and enjoy the house during her lifetime without damaging or diminishing it. However, when Mary dies, the house reverts back to John or his heirs.

In Roman law, the usufruct was considered a personal servitude, giving a real right. In modern civil law, the owner of the usufruct is similar to a life tenant, and the owner of the thing burdened is the naked owner.

Another related term is quasi-usufruct, which refers to the right to consume things that cannot be used without being expended or consumed, such as money or food. Unlike a perfect usufruct, a quasi-usufruct actually involves alteration and diminution of the property used.

For example, if John leaves $10,000 to Mary in his will as a quasi-usufruct, Mary has the right to use and spend the money during her lifetime, but when she dies, the $10,000 will be paid back to John's heirs.

These examples illustrate how liferent and quasi-usufruct are legal concepts that allow someone to use and enjoy property during their lifetime without owning it outright, and how the property reverts back to the original owner or their heirs when the right expires.