A more thorough explanation:

Reentry is a legal term that has different meanings related to property:

This refers to the repossession of real property by a previous landholder who has a future interest in the property. They hold the right to repossess the property if the current landholder breaches a condition of the grant through which they held the property. This is also known as the power of termination.

For example, if a person grants someone else a fee simple subject to a condition subsequent, they retain the right to repossess the estate if the grantee breaks the condition subsequent.

This refers to a landlord's right to repossess property that a tenant has abandoned or improperly holds. For certain types of tenancies, such as in New York, the landlord can reenter a vacant property after giving the tenant thirty days' notice.

For example, if a tenant stops paying rent and abandons the property, the landlord can reenter and take possession of the property.