swear

American  

[swair] / swɛər /

verb (used without object)

swore, sware, sworn, swearing

1. to make a solemn declaration or affirmation by some sacred being or object, as a deity or the Bible.

   Synonyms:

   avow, affirm, declare

2. to bind oneself by oath.

3. to give evidence or make a statement on oath.

   Synonyms:

   testify, depose

4. to use profane oaths or language.

   Don't swear in front of the children.

   Synonyms:

   imprecate

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verb (used with object)

swore, sware, sworn, swearing

1. to declare, affirm, attest, etc., by swearing by a deity, some sacred object, etc.

2. to affirm, assert, or say with solemn earnestness.

3. to promise or undertake on oath or in a solemn manner; vow.

4. to testify or state on oath.

   He swore it on the witness stand.

5. to take (an oath), as in order to give solemnity or force to a declaration, promise, etc.

6. to bind by an oath.

   to swear someone to secrecy.

noun

1. Informal. a profane or obscene word; curse word.

   If we said a swear, Mom made us put a quarter in the jar.

   Heads-up—this movie trailer is full of swears and is NSFW.

verb phrase

1. swear by

   1. to name (a sacred being or thing) as one's witness or guarantee in swearing.

   2. Informal. to have great confidence in; rely on.

      He swears by his dentist.

   3. to have certain knowledge of.

      I thought I saw him leaving, but I couldn't swear by it.

2. swear off to promise or resolve to give up something.

   I've decided to swear off the internet one day a week.

   Have you sworn off red meat?

3. swear in to admit to office or service by administering an oath.

   A new president will be sworn in today.

4. swear out to secure (a warrant for arrest) by making an accusation under oath.

swear British  

/ swɛə /

verb

1. to declare or affirm (a statement) as true, esp by invoking a deity, etc, as witness

2. (foll by by)

   1. to invoke (a deity, etc) by name as a witness or guarantee to an oath

   2. to trust implicitly; have complete confidence (in)

3. to curse, blaspheme, or use swearwords

4. (when tr, may take a clause as object or an infinitive) to promise solemnly on oath; vow

5. (tr) to assert or affirm with great emphasis or earnestness

6. (intr) to give evidence or make any statement or solemn declaration on oath

7. to take an oath in order to add force or solemnity to (a statement or declaration)

8. informal to assert emphatically

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noun

1. a period of swearing

Related Words

See curse.

Other Word Forms

• reswear verb
• swearer noun
• swearingly adverb

Etymology

Origin of swear

First recorded before 900; Middle English sweren, Old English swerian; cognate with German schwören, Old Norse sverja; akin to Gothic swaran “to swear”; answer

Example Sentences

“I came here and I walked around and I was like, I swear my family has been in this house,” she said.

From MarketWatch • Mar. 31, 2026

Still possible: Some eclipse-chasers swear by the sea for the best chances at a clear view of the event.

From The Wall Street Journal • Mar. 27, 2026

"It's a great contrast. The white, with the black," Trump told reporters as he showed them the ongoing work after a ceremony to swear in new the Homeland Security secretary, Markwayne Mullin.

From Barron's • Mar. 24, 2026

They are required to provide identification when registering to vote, and must swear under penalty of perjury, a felony, that they are eligible to vote and a U.S. citizen.

From Los Angeles Times • Mar. 2, 2026

Penelope could swear she saw Bertha sigh with relief as he went.

From "The Unseen Guest" by Maryrose Wood

Related Words

• affirm
• assert
• depose
• testify
• vow