A leaseholder is the person who holds a leasehold house or flat — they live in it (or use it) under a long lease. They often pay a ground rent to the freeholder, and they can usually sell the rest of the lease to someone else. This is not the same as a short-term tenant who rents from month to month, though actually both live in a place that belongs, in some sense, to someone else. The leaseholder’s rights are stronger and last many years.