swear to - definition and synonyms

phrasal verb [transitive] [usually in negatives]
present tense
I/you/we/theyswear to
he/she/itswears to
present participleswearing to
past tenseswore to
past participlesworn to
  1. swear to something to be completely certain of something

    I can’t swear to it, but I think I saw Joan yesterday.

See also main entry: swear