heretical doctrine; unorthodox belief
A formal, literary term for ideas or teachings that deviate from established orthodoxy, especially in religious or ideological contexts.
His claims were condemned by the church as heretical doctrine.
異端 is a more common and broader term for 'heresy' or 'unorthodoxy', while 異端邪説 specifically emphasizes the heretical nature of the doctrine or thought itself.
A yojijukugo composed of 異端 (heresy) and 邪説 (evil/wrong theory), literally meaning 'heretical and evil doctrine'.