/sweər/verb(past tenseswore, past participlesworn)
BAD LANGUAGE[I]›to use language which people think is rude or offensive: He was sent home because he swore at the teacher.She swore loudly and threw the box on the floor.
PROMISE[I, T]›to make a serious promise: [+ to do sth]I swear to tell the truth.[+ (that)]She swore that she was at home at the time of the accident.
TRUE[T]›used to say that you are sure something is true: [+ (that)]I could have sworn that she said she lived in Canterbury (= I was sure she lived in Canterbury, but now I have found that it is not true).