المعنى الاصطلاحي :

Anyone who is an example to be followed in evil and mischief.

الشرح المختصر :

"Qudwah sayyi’ah" (bad example) is a description applicable to anyone who goes against the methodology of the Messenger of Allah, may Allah's peace and blessings be upon him, while people tend to follow his example and imitate him, thereby learning evil actions, statements, and beliefs. Examples of "qudwah sayyi’ah" are: the devil, polytheists, religious innovators, dissolute parents, evil scholars, leaders of misguidance, etc.