testatio -onis f. calling to witness , or bearing witness.
testificatio -onis f. bearing witness , testifying; evidence, proof.
testificor -ari dep. to bear witness to , give evidence of; to show, bring to light; to call to witness.
testimonium -i n. witness , evidence; proof, indication.
testis (1) -is c. one who gives evidence , a witness; an eye-witness, a spectator.
testor -ari dep. (1) to bear witness to , give evidence of; to make known, publish, declare; as pass. to be attested, declared. (2) to make a will. (3) to call to witness.
BTW they are called "testicles" because they WITNESS to the procreative power of a man.
Persons#2, #3: Testify!
Person 2: Oh do you think he received?
Person 3: Do I think? Shit, I know he did.
The act of testifying normally involves babbling incoherently while sharing folksy stories of your nasty life being turned around because the creator of the universe decided to pay you a personal visit and issue a get out of jail free card. He's nice like that, and as a pensioner he has a free bus pass allowing him to travel anywhere in the world.
Hick: Well, I dun gone crashed mah car while drunk, and then I cheated on my sister with mah cousin. I's a sinner, but the baby Jesus came in to mah trailer and fixed me up good. Now I 'aint feelin' no guilt when I'm porking mah cousin.