Vader Eminent Domain Lawyer, Washington

A legal doctrine stating that if a person receives money or other property through no effort of his own, at the expense of another, the recipient should return the property to the rightful owner, even if the property was not obtained illegally. Most courts will order that the property be returned if the party who has suffered the loss brings a lawsuit.

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.

Land and the property permanently attached to it, such as buildings, houses, stationary mobile homes, fences and trees. In legalese, real estate is also called real property.

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.

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.

A proposal to enter into an agreement with another person. An offer must express the intent of the person making the offer to form a contract, must contain some essential terms--including the price and subject matter of the contract--and must be communicated by the person making the offer. A legally valid acceptance of the offer will create a binding contract.

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.

Insurance that reimburses a mortgage lender if the buyer defaults on the loan and the foreclosure sale price is less than the amount owed the lender (the mortgage plus the costs of the sale). A home buyer who makes less than a 20% down payment may have to purchase PMI.