Which legal term denotes an extension or modification to a previously executed will?

The term that denotes an extension or modification to a previously executed will is known as a codicil. A codicil serves as an addendum to the original will, allowing the testator to make changes, clarify provisions, or update information without the need to draft an entirely new will. This is particularly useful for individuals who wish to alter specific aspects of their estate planning while maintaining the overall framework established by the original document.

While an amendment might seem similar, it generally refers to changes made to a document or agreement, but in the context of wills, a codicil is the correct legal term. Testament is a term that refers to a will itself or the act of making one, and declaration typically pertains to a formal statement or announcement, which doesn’t specifically relate to modifying a will. Hence, understanding the unique function of a codicil is essential for proper estate planning and ensuring that one's wishes are accurately documented and legally recognized.