At common law, the broadest possible ownership interest in real estate, inheritable by any heir of the owner. fee simple absolute. A fee simple with no conditions placed upon it and that will endure as long as there are descendants of the original owner to inherit it. fee simple defeasible. A fee simple that is terminable despite the existence of heirs, because of the occurrence of a particular event or condition. fee simple determinable. A fee simple that terminates and reverts to the granto...