af·​fi·​da·​vit ˌa-fə-ˈdā-vət How to pronounce affidavit (audio)
: 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.”

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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 At the time of the shooting, the police affidavit says, Suady had an active felony warrant out of Florida for alleged interference in the custody of a minor child. Bill Lukitsch, Kansas City Star, 14 Feb. 2024 The daughter told police her father had days earlier paced by her bed, threatening to kill her, according to the affidavit. Peter Hermann, Washington Post, 13 Feb. 2024 Sixth Judicial District Administrator Sara Taylor submitted an affidavit describing extensive efforts by her team and other criminal justice and county leaders to explore other venues during the halt on trials. Tom Olsen, Twin Cities, 5 Feb. 2024 This map shows the location of the fires and Maynard’s locations as cited in the arrest affidavit. Bay Area News Group, The Mercury News, 2 Feb. 2024 But messages included in an FBI affidavit indicate that Trump’s company was part of the conversation in the meeting. Drew Harwell, Washington Post, 3 Feb. 2024 The information police received from Cash App revealed that 27 separate payment sources, including 25 debit or credit cards and two Cash App cards, were added to Reid's account from when his account was created in 2020 to Nov. 8, 2023, according to the affidavit. Stepheny Price, Fox News, 1 Feb. 2024 Detective Robinson showed him the beating video and the suspect admitted the video showed him, according to the affidavit. Emerson Clarridge, Fort Worth Star-Telegram, 1 Feb. 2024 Olsen, who lives in Arizona, drove to Denver on New Year’s Eve to visit his teenage son, the affidavit says. Emma Tucker, CNN, 30 Jan. 2024 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'affidavit.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

First Known Use

1515, in the meaning defined above

Time Traveler
The first known use of affidavit was in 1515

Dictionary Entries Near affidavit

Cite this Entry

“Affidavit.” Dictionary, Merriam-Webster, Accessed 26 Feb. 2024.

Kids Definition


af·​fi·​da·​vit ˌaf-ə-ˈdā-vət How to pronounce affidavit (audio)
: a sworn statement in writing

Legal Definition


af·​fi·​da·​vit ˌa-fə-ˈdā-vət How to pronounce affidavit (audio)
: a sworn statement in writing made especially under oath or on affirmation before an authorized magistrate or officer compare deposition, examination

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

More from Merriam-Webster on affidavit

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