noun, na-adjective
cruel and inhuman; brutal; merciless
Strongly negative term describing actions or character that are both cruel and lacking humanity. Often used in formal or written contexts.
その独裁者の残忍非道な行為は国際的に非難された。
The dictator's cruel and inhuman acts were condemned internationally.
彼は残忍非道な手段で敵を排除した。
He eliminated his enemies by brutal means.
A compound of 残忍 (ざんにん, 'brutal, cruel') and 非道 (ひどう, 'inhuman, unjust'). The combination intensifies the meaning to 'cruel and inhuman'.