brutal heart; beastly nature
Literary or formal term for a cruel, inhuman, or animal-like heart or nature. Not an everyday word; more common in written or elevated contexts.
His brutal heart was finally exposed.
beast in human form; human face but beastly heart
Compound of 獣 (beast) and 心 (heart, mind). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning 'brutal heart'.