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to run counter to; to go against; to disobey; to infringe
家臣が主君に叛いて城を明け渡した。
The retainer betrayed his lord and surrendered the castle.
親の期待に叛くことが彼にはできなかった。
He could not bring himself to go against his parents' expectations.
良心に叛く行為はいずれ自分を苦しめる。
Actions that go against one's conscience will eventually cause suffering.