testify

Etymology

PIE word *tréyes From Middle English testifien, borrowed from Old French testifier, from Latin testificārī, present active infinitive of testificor (“I bear witness”), from testis (“a witness”) + facere (“to make”). See -fy.

verb

1. To make a declaration, or give evidence, under oath.
   It was only after a decade away from Skipton that I was finally able to garner the courage to return and testify against my abuser. 29 August 2014, Ruzwana Bashir, “The untold story of how a culture of shame perpetuates abuse. I know, I was a victim”, in The Guardian
2. To make a statement based on personal knowledge or faith.