swear

Etymology 1

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”), Saterland Frisian 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 (svara, “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).

verb

1. (transitive, intransitive) To take an oath, to promise intensely, solemnly, and/or with legally binding effect.
   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.
   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.
4. (transitive) To administer an oath to (a person).
   Let the witness be sworn.
5. (transitive, intransitive) To use offensive, profane, or obscene language.
   An Australian was once appointed on contract, but he swore too much. 1956, Anthony Burgess, Time for a Tiger (The Malayan Trilogy), published 1972, page 38

Etymology 2

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

noun

1. A swear word.
   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. 1892, Robert Louis Stevenson, The Beach of Falesá
   [A]ccording to his kind the man would smile cynically, or look sad, or let out a swear or two. 1900, Joseph Conrad, Lord Jim, page v. 27

Etymology 3

From Middle English swere, swer, swar, from Old English swǣr, swār (“heavy, heavy as a burden, of great weight, oppressive, grievous, painful, unpleasant, sad, feeling or expressing grief, grave, slow, dull, sluggish, slothful, indolent, inactive from weakness, enfeebled, weak”), from Proto-West Germanic *swār, from Proto-Germanic *swēraz (“heavy”), from Proto-Indo-European *swer- (“heavy”). Cognate with West Frisian swier (“heavy”), Dutch zwaar (“heavy, hard, difficult”), German schwer (“heavy, hard, difficult”), Swedish svår (“heavy, hard, severe”), Latin sērius (“earnest, grave, solemn, serious”) and Albanian varrë (“wound, plague”).

adj

1. (Northern England, Scotland) Heavy.
2. (Northern England, Scotland) Top-heavy; too high.
3. (Northern England, Scotland) Dull; lazy; slow.
   Rise up gueedewife, an dinna be sweer, / B'soothan, b'soothan, / An deal yir chirity t' the peer, / An awa b'mony a toon. 1881, Walter Gregor, chapter XXII, in Notes on the Folk-lore of the North-east of Scotland, London: Folk-Lore Society, page 161
4. (Northern England, Scotland) Reluctant; unwilling.
   But faith, to glump ye I'd be sweer / I wish ye luck o' this new year 1805, John Stagg, “A New Year's Epistle”, in Miscellaneous Poems, Workington: W. Borrowdale, page 139
   My father will maybe be a wee sweer to take ye in, but ye maun make your way on him the best gate ye can; he has the best stockit pantry on Teviot head, but a bit of a Laidlaw's fault, complaining aye maist when he has least reason. 1822, James Hogg, The Three Perils of Man
5. (Northern England, Scotland) Niggardly.
   For if my Pen shall turn as Sweir's their Purse / I fear this is the last I'll write in Verse 1714, Robert Smith, Poems of Controversy Betwixt Episcopacy and Presbytery, 2nd edition, Edinburgh: R. Syme & Son, published 1853, page 61

noun

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

verb

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