testify

verb

tes·​ti·​fy ˈte-stə-ˌfī 

testified; testifying

intransitive verb

1

: to make a solemn declaration under oath for the purpose of establishing a fact (as in a court)

2

a

: to make a statement based on personal knowledge or belief : bear witness

b

: to serve as evidence or proof

3

: to express a personal conviction

transitive verb

1

a

: to bear witness to : attest

b

: to serve as evidence of : prove

2

: to declare under oath before a tribunal or officially constituted public body

3

archaic

a

: to make known (a personal conviction)

b

: to give evidence of : show

testifier

ˈte-stə-ˌfī(-ə)r 

noun

Synonyms

• attest
• depose
• swear
• witness

Examples of testify in a Sentence

She refused to testify about who had given her the information.

She testified before Congress today.

He agreed to testify against his drug dealer.

He testified that he'd seen two people leave the building on the night of the murder.

These statistics testify that the program is working.

Several people testified during the revival meeting.

Recent Examples on the Web

But Cohen has testified there was no retainer and Trump directed the payments to women. —Bart Jansen, USA TODAY, 14 Apr. 2024

Hill and jurors from the trial testified during the January hearing. —Chris Pandolfo, Fox News, 12 Apr. 2024

Detective testifies about discovering children’s remains Months after JJ and Tylee went missing, local law enforcement located their remains on Chad Daybell’s East Idaho property on June 9, 2020. —Alex Brizee, Idaho Statesman, 11 Apr. 2024

In Wednesday’s proceedings, two psychologists testified. —Marlene Lenthang, NBC News, 11 Apr. 2024

In what was seen as the crucial blunder of the trial, the prosecution asked Mr. Simpson, who was not called to testify, to try on the gloves. —Robert D. McFadden, New York Times, 11 Apr. 2024

His plea agreement does not require him to testify at Trump’s hush money criminal trial, which is scheduled to start with jury selection Monday. —Michael R. Sisak, Fortune, 10 Apr. 2024

Prather testified that the nephew had access to her computer. —The Enquirer, 10 Apr. 2024

Several of Daybell's five children also plan to testify about their mother's health, Prior said. —Meredith Deliso, ABC News, 10 Apr. 2024

Word History

Etymology

Middle English testifien, from Anglo-French testifier, from Latin testificari, from testis witness

First Known Use

14th century, in the meaning defined at intransitive sense 2a

Phrases Containing testify

• testify for the defense/prosecution

Kids Definition

testify

verb

tes·​ti·​fy ˈtes-tə-ˌfī 

testified; testifying

1

a

: to make a statement based on personal knowledge or belief

could testify to the student's devotion to her studies

b

: to make a formal statement of what one swears is true

testified in court

2

: to give outward proof : serve as a sign of

yawns testifying to fatigue

testifier

-ˌfī(-ə)r 

noun

Legal Definition

testify

verb

tes·​ti·​fy ˈtes-tə-ˌfī 

testified; testifying

intransitive verb

: to make a solemn declaration under oath or affirmation for the purpose of establishing a fact : give testimony

transitive verb

: to declare in testimony

testifier noun

Etymology

Latin testificari, from testis witness