verb, directional · to reveal a secret, confidential information, or specialized skills to people outside a specific group

这个家传秘方从不向外传。

verb · to be circulated as news or rumored among the public

坊间外传他即将辞去总裁的职务。

noun · unofficial biography (as opposed to official dynastic biography)

他写了一本关于那位名将的外传。