tes ‧ ta ‧ ment /ˈtestəmənt/ BrE AmE noun [countable] formal
[ Date: 1200-1300 ; Language: Latin ; Origin: testamentum 'last will' , from testari 'to be a witness, make a will' , from testis ; ⇨ ↑ testify ]
1 . be a testament to something proving or showing very clearly that something exists or is true:
The aircraft’s safety record is a testament to its designers’ skill.
2 . a ↑ will 2 (2)
—testamentary /ˌtestəˈment ə ri◂/ adjective
⇨ ↑ New Testament , ↑ Old Testament