undermining
chess tactic in which a defensive piece is captured, leaving one of the opponent's pieces undefended or under-defended
en-GB/ˌʌndəˈmaɪnɪŋ/
en-US/ˈʌndɚˌmaɪnɪŋ/
chess tactic in which a defensive piece is captured, leaving one of the opponent's pieces undefended or under-defended