undermine
🇺🇸
/ˌʌndərˈmaɪn/
🇬🇧
/ˌʌndəˈmaɪn/
to slowly weaken or damage something, like someone's confidence or power
Spreading false rumors can undermine trust between friends.
to weaken the base or foundation of something by digging under it
Water can undermine the foundation of a building over time.