for ‧ swear /fɔːˈsweə $ fɔːrˈswer/ BrE AmE verb ( past tense forswore /-ˈswɔː $ -ˈswɔːr/, past participle forsworn /-ˈswɔːn $ -ˈswɔːrn/) [transitive] formal
[ Language: Old English ; Origin: forswerian ]
to stop doing something or promise that you will stop doing something SYN renounce :
We are forswearing the use of chemical weapons for any reason.