Abatement clause – this term finds application within the area of Contract Law. There abatement clause refers to a clause, stipulated in rental agreements, that entitles the tenant to cancel it. Such right occurs when a force majeure event or other unpredicted circumstance prevents the further occupancy of the rented real estate. Most important, such cancellation of the tenant agreement should bring no penalties towards the tenant. It is considered as non-guilty termination of the tenant contract. This is due to the technical impossibility to continue the occupation.
See also http://definitions.uslegal.com/a/abatement-clause .