Which term describes an estate existing for a lifetime or forever?

The term that describes an estate existing for a lifetime or forever is "freehold." A freehold estate is characterized by the owner's indefinite duration of ownership. This can last for the duration of the owner's life or continue indefinitely, which aligns with the concept of ownership being held without a set expiration. Freehold estates are typically contrasted with leasehold estates, which have a defined time limit.

In this context, while "life estate" specifically refers to an estate that is held for the duration of a person's life, a freehold estate is broader and includes not only life estates but also the possibility of an estate lasting indefinitely beyond any individual's lifetime. Thus, freehold encompasses both the idea of lifetime ownership and the potential for perpetual ownership, which is why it is the most accurate term for an estate existing for a lifetime or forever.