Final answer:
A reversionary estate is an estate in land that places certain restrictions on an owner's use of the property and contains an automatic reverter clause.
Step-by-step explanation:
An estate in land that places certain restrictions on an owner's use of the property and contains an automatic reverter clause is known as a reversionary estate.
Reversionary estates are created when a grantor transfers property to a grantee, but retains the right to regain possession of the property if a specified condition is not met.