1. to reject, renounce, or promise to give up something
Usage: often used with 'swear' or 'oath' in formal or solemn contexts
2. to swear falsely; to commit perjury
Usage: archaic or legal usage

Examples

• She foreswore alcohol after deciding to live a healthier lifestyle.
• The candidate foreswore negative campaigning and focused on policy instead.
• He foreswore his former beliefs and adopted a new philosophy.
• The monk foreswore worldly possessions to pursue a spiritual life.
• They foreswore violence as a means of resolving their dispute.
• The athlete foreswore sugary drinks to improve her performance.