intransitive verb swore, sworn, swearing swear′·ing

1. to make a solemn declaration with an appeal to God or to something held sacred for confirmation to swear on one's honor
2. to make a solemn promise; vow
3. to use profane or obscene language; curse
4. Law to give evidence under oath

Etymology: ME swerien < OE swerian, akin to Ger schwören < IE base *swer-, to speak > OSlav svariti, to revile

transitive verb

1. to declare solemnly in the name of God or of something held sacred
2. to pledge or vow on oath
3. to assert or promise with great conviction or emphasis
4. to take (an oath) by swearing
5. to administer a legal oath to