A more thorough explanation:

Definition: Usucapio is a legal term used in Roman and civil law. It refers to the acquisition of ownership by long possession that began in good faith. This means that if someone possesses something for a certain period of time, they can become the legal owner of it, even if they did not originally own it.

For example, if someone lives in a house for a certain number of years without the owner's permission, they may be able to claim ownership of the house through usucapio. In classical law, the required periods were one year for movable property and two years for land. Under Justinian, the period was three years for movable property and a minimum of ten years for land.

Usucapio is also known as usus, usucaption, or usucapion.

Example: John has been using a piece of land that belongs to his neighbor for over ten years. He has been using it openly and without any objection from his neighbor. According to the principle of usucapio, John may be able to claim ownership of the land because he has possessed it for the required period of time.

This example illustrates how usucapio can be used to acquire ownership of property through long possession. Even if John did not originally own the land, his long possession of it can give him legal ownership through usucapio.