Lyons Real Estate Lawyer, New York

Principles of international law so fundamental that no nation may ignore them or attempt to contract out of them through treaties. For example, genocide and participating in a slave trade are thought to be jus cogens.

A meeting of the minds. An agreement is made when two people reach an understanding about a particular issue, including their obligations, duties and rights. While agreement is sometimes used to mean contract -- a legally binding oral or written agreement -- it is actually a broader term, including understandings that might not rise to the level of a legally binding contract.

A seller's taking advantage of a buyer due to their unequal bargaining positions, perhaps because of the buyer's recent trauma, physical infirmity, ignorance, inability to read or inability to understand the language. The unfairness must be so severe that it is shocking to the average person. It usually includes the absence of any meaningful choice on the part of the buyer and contract terms so one-sided that they unreasonably favor the seller. A contract will be terminated if the buyer can prove unconscionability.

The act of changing a written contract when one of the parties can prove that the actual agreement was different than what's written down. The changes are usually made by a court when both parties overlooked a mistake in the document, or when one party has deceived the other.

The loss of property or a privilege due to breaking a law. For example, a landlord may forfeit his or her property to the federal or state government if the landlord knows it is a drug-dealing site but fails to stop the illegal activity. Or, you may have to forfeit your driver's license if you commit too many moving violations or are convicted of driving under the influence of alcohol or drugs.

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.

One who receives property from someone who has died. While the traditional meaning includes only those who had a legal right to the deceased person's property, modern usage includes anyone who receives property from the estate of a deceased person.