testifier

intransitive verb testified, testifying

1. to make a serious declaration to substantiate a fact; bear witness or give evidence, esp. under oath in court
2. to be evidence or an indication: a look testifying to his impatience

Origin: ME testifien < L testificari < testis, a witness (prob. < *tri-sto-, standing as a third < tri-, tri- + base of stare, stand) + facere, to make, do

transitive verb

1. to bear witness to; affirm; declare, esp. under oath in court
2. to be evidence of; indicate
3. Archaic to profess or proclaim publicly