foresworn
/ˈfɔːrsɔːrn/Definitions
1. adjective
given one’s word or promise under a penalty, especially by oath, and failed to keep it
“The politician was accused of being foresworn in his dealings with the investor.”
2. noun
a person who has given their word and failed to keep it
“The foresworn individual was shunned by the community for their deceit.”