noun

• (countable) A guarantee that a certain outcome or obligation will be fulfilled; security.
  "Those who have had the care and government of politic societies introduced coinage, as a remedy of those two inconveniences. The stamp was a warranty of the public, that, under such a denomination, they should receive a piece of such a weight, and such a fineness; […]"
• (countable, law, real estate, obsolete) A legal agreement that was a real covenant and ran with the land: The grantor of a piece of real estate held in freehold, and their heirs, were required to officially guarantee their claim and plead their case for the title. If evicted by someone with a superior claim (paramount title), they were also required to hand over other real estate of equal value in recompense. It has now been replaced by personal covenants and the covenant of warranty.
• (countable, law, real estate, obsolete) A legal agreement that was a real covenant and ran with the land: The grantor of a piece of real estate held in freehold, and their heirs, were required to officially guarantee their claim and plead their case for the title. If evicted by someone with a superior claim (paramount title), they were also required to hand over other real estate of equal value in recompense. It has now been replaced by personal covenants and the covenant of warranty.
• (countable, law) A legal agreement, either written or oral (an expressed warranty) or implied through the actions of the buyer and seller (an implied warranty), which states that the goods or property in question will be in exactly the same state as promised, such as in a sale of an item or piece of real estate.