Rescinder is a legal term that refers to a decision that has been canceled or annulled. It is often used in reference to contracts, agreements, and other legal documents that are no longer valid. Some synonyms for rescinder include revocation, repeal, cancellation, nullification, and termination. These words often describe the same legal action of ending a contract or agreement, but vary in emphasis and connotation. Revocation suggests a more deliberate and intentional action, while nullification emphasizes the invalidity of the original decision. Regardless of the word used, rescinding a contract or agreement requires careful consideration and legal expertise.