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”), 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).

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

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”), Danish svær (“heavy, hard, severe”), Swedish svår (“heavy, hard, severe”), Latin sērius (“earnest, grave, solemn, serious”) and Albanian varrë (“wound, plague”).