warranty: in the context of a legal contract, a warranty is a promise or assurance in the contract that a particular thing will be done, or that a particular fact or matter is true; if a warranty is breached by the contractual party giving it, the innocent party will have a claim for breach of contract, the remedies for which could include financial damages; typically used in share purchase agreements and business sale contracts, where a buyer will obtain warranties from the seller as to the state of the company or business being acquired.