Definition of "swore"

If that were all, for some have swore / As false as they, if th' did no more […]

1663, [Samuel Butler], “The Second Part of Hudibras”, in Hudibras. The First and Second Parts. […], London: […] John Martyn and Henry Herringman, […], published 1678; republished in A[lfred] R[ayney] Waller, editor, Hudibras: Written in the Time of the Late Wars, Cambridge: University Press, 1905, canto II, page 133

" […] I have 'swore off' smoking. But you shall have your pipe (the old tobacco) or cigars among the books. It will be quite a delight."

1990 , R. H. Super, quoting Anthony Trollope, The Chronicler of Barsetshire: A Life of Anthony Trollope‎, page 337

“Were it not for the fancy French and Latin in it, I'd have swore it was the sort of thing I do not print as a rule, but being as how the order was from one of the members upstairs...”

2014 January 14, Roberta Rogow, The Problem of the Surly Servant‎, page 109