af·​fi·​da·​vit | \ ˌa-fə-ˈdā-vət How to pronounce affidavit (audio) \

Definition of affidavit

: a sworn statement in writing made especially under oath or on affirmation (see affirmation sense 2) before an authorized magistrate or officer The witness's affidavit was presented to the court as evidence.

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Promises, Promises: The History of Affidavit, Affiance, & Fiancé

Affidavit refers to a written promise, and its Latin roots connect it to another kind of promise in English. It comes from a past tense form of the Latin verb affidare, meaning “to pledge”; in Latin, affidavit translates to “he or she has made a pledge.”

Affidare is also the root of affiance, an archaic English noun meaning “trust, faith, confidence,” “marriage contract or promise,” or a meaning that has completely fallen from use, “close or intimate relationship.” More familiar to modern English speakers is the verb affiance, meaning “to promise in marriage” or “to betroth.” It usually appears as a fancy-sounding participial adjective:

I like to give affianced friends a copy of Rebecca Mead’s book “One Perfect Day,” which exposes the ridiculous wedding industry.
—Mollie Hemingway, The Federalist, 7 October 2014

Affiance came through French to English in the 14th century, and, nearly 500 years later, the related French words fiancé and fiancée were added to English. Etymologically speaking, a fiancé or fiancée is a “promised one.”

Did You Know?

In Latin, affidavit means "he (she) has sworn an oath", and an affidavit is always a sworn written document. If it contains a lie, the person making it may be prosecuted. Affidavits are often used in court when it isn't possible for someone to appear in person. Police officers must usually file an affidavit with a judge to get a search warrant. Affidavits (unlike similar signed statements called depositions) are usually made without an opposing lawyer being present and able to ask questions.

Examples of affidavit in a Sentence

We have a signed affidavit stating that the two men were seen entering the building.
Recent Examples on the Web According to an affidavit, Campbell confirmed in a text message that the person was, in fact, an undercover officer. Cameron Knight,, "Documents: 'Members of the Cincinnati Police Department' may have 'tipped off' nightclubs about raids," 14 Feb. 2020 The charges stem from an incident that occurred Dec. 1, according to an affidavit obtained by Augusta Fox affiliate Fox 54 News Now. Stephanie Toone, ajc, "Georgia couple accused of molesting, taking video of 8-year-old girl," 3 Feb. 2020 Her body was found on Dec. 19 stuffed into a duffel bag in the trunk of a car parked in the backyard of the house where Fieramusca, also 33, lived near Jersey Village, according to an affidavit of arrest. Hannah Dellinger, Houston Chronicle, "Houston woman charged with capital murder in Heidi Broussard case," 28 Jan. 2020 Four inmates told State Police that O'Donnell had talked with them about killing Collins-Smith's ex-husband, Phil Smith, and arranging to have the death look like suicide, according to an affidavit filed Tuesday. CBS News, "New twist in case of woman accused of killing former Arkansas state senator," 15 Jan. 2020 According to an affidavit, police responded to the apartment around 8:23 p.m. Friday after Parker called 911 saying his girlfriend was not breathing. Katie Rice,, "DeLand man facing murder charge after girlfriend dies following ‘vicious assault’," 10 Dec. 2019 According to an affidavit released in July, police said O'Donnell was filmed removing security cameras from the former lawmaker's home on May 28. John Moritz, Arkansas Online, "Prosecutor in death of former state senator asks departure; trial of woman sees another turn," 7 Dec. 2019 Witnesses said Sherra Wright was the mastermind of a plan to hav e two men kill Lorenzen Wright at his Atlanta home, but that attempt failed, according to an affidavit. Adrian Saniz,, "Convict charged in former NBA player’s killing to face judge," 4 Dec. 2019 Though neither is a rower, the parents saw being a coxswain as their daughters’ ticket into the private college, which has an acceptance rate of 13%, according to an affidavit filed in federal court. Matt Hamilton, Los Angeles Times, "Lori Loughlin faces moment of truth in college admissions scandal as daughters exit USC," 22 Oct. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'affidavit.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of affidavit

1515, in the meaning defined above

History and Etymology for affidavit

borrowed from Medieval Latin affīdāvit "he/she has made a pledge," third person singular perfect indicative active of affīdāre — more at affiance entry 1

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Time Traveler for affidavit

Time Traveler

The first known use of affidavit was in 1515

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Statistics for affidavit

Last Updated

19 Feb 2020

Cite this Entry

“Affidavit.” Dictionary, Merriam-Webster, Accessed 23 Feb. 2020.

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How to pronounce affidavit (audio)

English Language Learners Definition of affidavit

law : a written report which is signed by a person who promises that the information is true


af·​fi·​da·​vit | \ ˌa-fə-ˈdā-vət How to pronounce affidavit (audio) \

Kids Definition of affidavit

: a written statement signed by a person who swears that the information is true


af·​fi·​da·​vit | \ ˌa-fə-ˈdā-vət How to pronounce affidavit (audio) \

Legal Definition of affidavit

: a sworn statement in writing made especially under oath or on affirmation before an authorized magistrate or officer — compare deposition, examination

History and Etymology for affidavit

Medieval Latin, he/she has pledged faith, third singular perfect of affidare — see affiant

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More from Merriam-Webster on affidavit

Spanish Central: Translation of affidavit

Nglish: Translation of affidavit for Spanish Speakers

Britannica English: Translation of affidavit for Arabic Speakers Encyclopedia article about affidavit

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