Meaning

verb utter obscenities or profanities

verb to declare or affirm solemnly and formally as true

verb promise solemnly; take an oath

originFrom 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…

Etymology from Wiktionary, CC BY-SA 3.0