Other forms: sworn, swore, swearing, swears
Swear has two lives. One is the solemn promise: a witness swears to tell the truth with a hand raised, a president swears an oath, a soldier swears loyalty. The other is what you do when you drop something heavy on your foot.
For the promise sense: you swear to do something, swear that you saw it, swear on your life; a judge is sworn in; two people can be sworn enemies. For the rude sense: swearing at the referee, a swear word, do not swear in front of your grandmother. There is also plain emphasis — I swear I put the keys here. Two useful phrases: to swear by something is to trust it completely, and to swear someone to secrecy is to make them promise to keep quiet. The verb is irregular: swear, swore, sworn.
1verbvowTo promise something in a serious and formal way, sometimes in front of a court or an official.~96%
“Witnesses swear to tell the truth before they give evidence.”
2verbswearTo use rude or offensive words.~2%
“He swears when he is driving and at no other time.”
synonyms: curse
3verbgreatTo say with great force that something is true.~2%
“I swear the door was locked when we left.”
Shares are an estimate: a language model read 10 sentences found in the wild and placed 10 of them on a sense — a count of our sample, not a measurement of English.
Swear comes from Old English swerian, to swear or take an oath of office, from Proto-Germanic swarjaną, to speak or swear, and a Proto-Indo-European root swer- meaning to swear. The oath sense is the original one in every Germanic language — Dutch zweren, German schwören, Icelandic sverja. The bad-language sense grew out of it later, from swearing oaths too lightly.
Proto-Indo-European
*swer- — to swear
Proto-Germanic
*swarjaną — to speak, swear
Proto-West Germanic
*swarjan
Old English
swerian — to swear, take an oath of office
Middle English
sweren
English, today
swear
From Middle English sweren, swerien, from Old English swerian (“to swear, take an oath of office”), from Proto-West Germanic swarjan, from Proto-Germanic swarjaną (“to speak, swear”), from Proto-Indo-European swer- (“to swear”). Cognate with West Frisian swarre (“to swear”), stq swera (“to swear”), Dutch zweren (“to swear, vow”), Low German swören (“to swear”), sweren, German schwören (“to swear”), Danish sværge, Swedish svära (“to swear”), Icelandic sverja (“to swear”), Russian свара (“quarrel”). Also cognate to Albanian var (“to hang, consider, to depend from”) 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. Matthew 5:33-37) and invoking God’s name in particular (i.e. frequent swearing was considered similar to the use of obscene words).
Etymology from Wiktionary, CC BY-SA