testify

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.

testify (third-person singular simple present testifies, present participle testifying, simple past and past participle testified) (transitive, intransitive)

1. To make a declaration, or give evidence, under oath.
   • 2014, Ruzwana Bashir, "The untold story of how a culture of shame perpetuates abuse. I know, I was a victim", The Guardian, 29 August 2014:

     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.

   • Bible, Numbers xxxv. 30

     One witness shall not testify against any person to cause him to die.

2. To make a statement based on personal knowledge or faith.
   • Bible, John iii. 11

     We speak that we do know, and testify that we have seen; and ye receive not our witness.

• bear witness

• attest
• testimony
• testimonial

• compel testimony

• testify in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.
• testify in The Century Dictionary, New York, N.Y.: The Century Co., 1911.