A more thorough explanation:

Definition: Pro derelicto means "as derelict or abandoned." It refers to property that is subject to usucapio, which is the acquisition of ownership by long possession begun in good faith.

Example: If someone finds an old, abandoned house and lives in it for a certain period of time, they may be able to claim ownership of the property through usucapio. This property would then be considered pro derelicto.

This term is often used in legal contexts, particularly in Roman and civil law. It is important to note that the acquisition of ownership through usucapio requires certain conditions to be met, such as possession in good faith and for a certain period of time.