testament

/ˈtɛst.ə.mənt/
noun
  1. 1

    A solemn, authentic instrument in writing, by which a person declares his or her will as to disposal of his or her inheritance (estate and effects) after his or her death, benefiting specified heir(s).

  2. 2

    One of the two parts to the scriptures of the Christian religion: the New Testament, considered by Christians to be a continuation of the Hebrew scriptures, and the Hebrew scriptures themselves, which they refer to as the Old Testament.

  3. 3

    A tangible proof or tribute.

    The ancient aqueducts are a testament to the great engineering skill of the Roman Empire.

  4. 4

    A credo, expression of conviction

    The prime minister's speech was a glowing testament to the cabinet's undying commitment to the royal cause.

Source: https://en.wiktionary.org/wiki/testament