[tes.ti.fy] vb -fied ; -fy.ing [ME testifien, fr. L testificari, fr. testis witness] vi (14c) 1 a: to make a statement based on personal knowledge or belief: bear witness b: to serve as evidence or proof
2: to express a personal conviction
3: to make a solemn declaration under oath for the purpose of establishing a fact (as in a court) ~ vt 1 a: to bear witness to: attest b: to serve as evidence of: prove
2. archaic a: to make known (a personal conviction) b: to give evidence of: show
3: to declare under oath before a tribunal or officially constituted public body -- tes.ti.fi.er n