testify

American  

[tes-tuh-fahy] / ˈtɛs təˌfaɪ /

verb (used without object)

testified, testifying

1. to bear witness; give or afford evidence.

2. Law. to give testimony under oath or solemn affirmation, usually in court.

3. to make solemn declaration.

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verb (used with object)

testified, testifying

1. to bear witness to; affirm as fact or truth; attest.

2. to give or afford evidence of in any manner.

   Synonyms:

   prove, signify, show, indicate

3. Law. to state or declare under oath or affirmation, usually in court.

4. to declare, profess, or acknowledge openly.

testify British  

/ ˈtɛstɪˌfaɪ /

verb

1. (when tr, may take a clause as object) to state (something) formally as a declaration of fact

   I testify that I know nothing about him

2. law to declare or give (evidence) under oath, esp in court

3. to be evidence (of); serve as witness (to)

   the money testified to his good faith

4. (tr) to declare or acknowledge openly

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Other Word Forms

• pretestify
  verb (used with object)
• retestify
  verb
• testification
  noun
• testifier
  noun
• untestifying
  adjective

Etymology

Origin of testify

1350–1400; Middle English testifyen < Latin testificārī to bear witness, equivalent to testi ( s ) witness + -ficārī -fy

Explanation

To testify is to make a statement or provide evidence, usually in court. Witnesses testify for the prosecution or defense. If you've ever seen a TV show about lawyers, you've probably seen someone testifying: putting their hand on the Bible, sitting in the witness seat, and telling what they know about a case. Testifying is serious business, but it doesn't always happen in court: If someone knows you're good at math, they can testify to your math skills. Or if you've been to a restaurant, you can testify to your friends that it has awesome desserts.

Example Sentences

Altman is expected to testify as early as next week.

From Barron's • May 5, 2026

Macklem and Rogers will also testify before Canada’s senate on Wednesday.

From The Wall Street Journal • May 4, 2026

The settlement comes just two weeks ahead of a scheduled trial, where both stars were expected to testify.

From BBC • May 4, 2026

“You take what the world cast aside and breathe spirit into it, insisting that the overlooked can speak, that the discarded can testify, that the everyday can dream.”

From Los Angeles Times • May 3, 2026

It didn’t mean she wouldn’t testify against us, any of us, if she had the occasion.

From "The Handmaid's Tale" by Margaret Atwood

Related Words

• announce
• argue
• assert
• declare
• depose
• indicate
• swear