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

Cicero testified that the blood stains and patterns on the tree led him to him believe the attack on Libby started at the tree, with swipes of a weapon possibly causing the splatter on the tree. —Jeremy Edwards, ABC News, 29 Oct. 2024

Coy used a flashlight to spot Hill in the garage and told him to come out and show himself, the officer testified. —CBS News, 29 Oct. 2024

During an onstage conversation at the 25th annual New Yorker Festival in New York City, Shepard, 49, testified to the 49-year-old actor’s humility, recalling Cooper’s reaction to receiving the title of PEOPLE’s Sexiest Man Alive. —Brendan Le, People.com, 28 Oct. 2024

While Abby’s body was discovered fully clothed – in Libby’s clothes – Libby was discovered nude, Kohr testified, according to WRTV. —Zoe Sottile, CNN, 28 Oct. 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