also: ことごころ
noun
treachery; treacherous designs
Refers to disloyal or treacherous intentions, often in historical or literary contexts. Modern usage is rare; more common words like 裏切り or 謀反 are preferred.
彼の異心を見抜けなかったのが敗因だ。
The reason for the defeat was that we failed to see through his treachery.
家臣に異心ありと疑われた。
He was suspected of having treacherous intentions by his retainers.
Obsolete reading; it is out-dated kana usage.
Out-dated kanji usage; rarely used in modern writing.
Composed of 異 (different, unusual) and 心 (heart, mind), suggesting a heart that deviates from loyalty. The exact historical derivation is uncertain; the spelling is conventionally associated with treacherous intent.