• (RP) IPA: /swɛə/
• (America) IPA: /swɛɚ/

From Middle English sweren, swerien, from Old English swerian, from Proto-West Germanic *swarjan, from Proto-Germanic *swarjaną, from Proto-Indo-European *swer-.

Cognate with Western Frisian swarre, Saterland Frisian swera, Dutch zweren, Low German swören, sweren, German schwören, Danish sværge, Swedish svära, Icelandic sverja, Russian свара. Also cognate to Albanian var through Proto-Indo-European.

The original sense in all Germanic languages is “to take an oath”. The sense “to use bad language” developed in Middle English and is based on the Christian prohibition against swearing in general (cf. Gospel of Matthew 5:33-37) and invoking God’s name in particular (i.e. frequent swearing was considered similar to the use of obscene words).

swear (swears, present participle swearing; simple past swore, past participle sworn)

1. (ambitransitive) To take an oath, to promise intensely, solemnly, and/or with legally binding effect.

   Synonyms: pledge, vow

   The knight swore not to return to the palace until he had found the treasure.

2. (transitive) To take an oath that an assertion is true.

   Synonyms: depose, affirm, testify

   The witness swore that the person she had seen running out of the bank was a foot shorter than the accused.

3. (transitive) To promise intensely that something is true; to strongly assert.

   I swear I don't know what you're talking about.

   My little brother is such a pest, I swear.

   • 1920, Mary Roberts Rinehart, Avery Hopwood, chapter I, in The Bat: A Novel from the Play (Dell Book; 241), New York, N.Y.: Dell Publishing Company, →OCLC ↗, [https://babel.hathitrust.org/cgi/pt?id=hvd.hwptej;view=1up;seq=5 page 01]:

     The Bat—they called him the Bat. […]. He'd never been in stir, the bulls had never mugged him, he didn't run with a mob, he played a lone hand, and fenced his stuff so that even the fence couldn't swear he knew his face.

4. (transitive) To administer an oath to (a person).

   Let the witness be sworn.

5. (ambitransitive) To use offensive, profane, or obscene language.

   Synonyms: curse, execrate, turn the air blue, Thesaurus:swear

• French: jurer
• German: schwören
• Italian: giurare
• Portuguese: jurar
• Russian: кля́сться
• Spanish: jurar

• French: jurer, gronder
• German: schimpfen, fluchen
• Italian: insultare, bestemmiare
• Portuguese: praguejar, xingar
• Russian: руга́ться
• Spanish: blasfemar, renegar, jurar, echar ternos, maldecir

From the above verb, or from Middle English sware, from Old English swaru, from Proto-Germanic *swarō.

swear (plural swears)

1. A swear word.

   Synonyms: curse, expletive, four-letter word, Thesaurus:swear word

   • 1892, Robert Louis Stevenson, The Beach of Falesá:

     You might think it funny to hear this Kanaka girl come out with a big swear. No such thing. There was no swearing in her — no, nor anger; she was beyond anger, and meant the word simple and serious.

From Middle English swere, swer, swar, from Old English swǣr, swār, from Proto-West Germanic *swār, from Proto-Germanic *swēraz, from Proto-Indo-European *swer-.

Cognate with Western Frisian swier, Dutch zwaar, German schwer, Swedish svår, Latin sērius and Albanian varrë.

swear (comparative swearer, superlative swearest)

1. (Northern England, Scotland) Heavy.

   Synonyms: massive, massy, weighty

2. (Northern England, Scotland) Top-heavy; too high.

   Synonyms: overbalanced

3. (Northern England, Scotland) Dull; lazy; slow.

   Synonyms: idle, work-shy, Thesaurus:lazy

4. (Northern England, Scotland) Reluctant; unwilling.

   Synonyms: disinclined, loath

5. (Northern England, Scotland) Niggardly.

   Synonyms: miserly, penurious, Thesaurus:stingy

swear (plural swears)

1. (Northern England, Scotland) A lazy time; a short rest during working hours (especially field labour); a siesta.

   Synonyms: nap, undermeal

swear (swears, present participle swearing; simple past and past participle sweared)

1. (Northern England, Scotland) To be lazy; rest for a short while during working hours.

   Synonyms: laze about, loaf, take it easy