Which term describes a legally enforceable agreement between two or more parties?

The term that describes a legally enforceable agreement between two or more parties is a contract. A contract is a binding agreement that creates mutual obligations enforceable by law. It typically outlines the terms under which the parties agree to exchange goods, services, or other considerations. Contracts can be written or verbal, although certain types of contracts must be in writing to be enforceable under the Statute of Frauds.

The other terms mentioned do not fit the definition of a legally enforceable agreement in the same way. A memorandum refers to a written record or communication but does not inherently possess enforceability as it may not contain all necessary elements of a contract. An accord is an agreement that resolves a dispute, but it may not be enforceable until a formal contract is created. Theory generally pertains to abstract principles or concepts rather than legal agreements. Thus, the most accurate term for a legally binding agreement between parties is indeed a contract.