Greig Real Estate Lawyer, New York

An unforeseen and uncontrollable event that excuses a party to a contract from performing his or her duties under that contract. For example, a landlord can break a lease if the property she agreed to rent accidentally burns down before the tenants move in.

A method for the formal delivery of court papers that takes the place of personal service. Personal service means that the papers are placed directly into the hands of the person to be served. Substituted service, on the other hand, may be accomplished by leaving the documents with a designated agent, with another adult in the recipient's home, with the recipient's manager at work or by posting a notice in a prominent place and then using certified mail to send copies of the documents to the recipient.

Another term for real estate. It includes land and things permanently attached to the land, such as trees, buildings, and stationary mobile homes. Anything that is not real property is termed personal property.

A deed that transfers whatever ownership interest the transferor has in a particular property. The deed does not guarantee anything about what is being transferred, however. For example, a divorcing husband may quitclaim his interest in certain real estate to his ex-wife, officially giving up any legal interest in the property. Compare grant deed.

A computer-based service that provides real estate professionals with detailed listings of most homes currently on the market. Much of the information can now be obtained by the public through websites like www.realtor.com.

A legal doctrine that requires landlords to offer and maintain livable premises for their tenants. If a landlord fails to provide habitable housing, tenants in most states may legally withhold rent or take other measures, including hiring someone to fix the problem or moving out. See constructive eviction.

Any control over property. If you give away property but keep an incident of ownership--for example, you give away an apartment building but retain the right to receive rent--then legally, no gift has been made. This distinction can be important if you're making large gifts to reduce your eventual estate tax.

A statement included in a patent application that describes the structure of an invention in precise and exact terms, using a long established formal style and precise terminology. Patent claims serve as a way for the U.S. Patent and Trademark Office (PTO) to determine whether an invention is patentable, and as a way for a court to determine whether a patent has been infringed. In concept, a patent claim marks the boundaries of the patent in the same way as the legal description in a deed specifies the boundaries of the property.

A provision in a contract stating that some or all of the terms of the contract will be altered or voided by the occurrence of a specific event. For example, a contingency in a contract for the purchase of a house might state that if the buyer does not approve the inspection report of the physical condition of the property, the buyer does not have to complete the purchase.