"What is a Su Jia Di Zi?"
I would rather best leave this response to my dear friend (and little sister) Chen Jing Jing:
"Su jia di zi means those people who either previously stayed at the temple as monks or never were monks, but they had monk masters. A su jia di zi practices kong fu, a lot of them are excellent kong fu players, they normally wear normal clothes, with hair and have a sexual life. If needed, they should do everything they can to defend the fame of the temple and fight the offenders. Theoretically, they don't have to study Buddhism, (they don't have to question the meaning of life :-))"
I couldn't have said it better myself. (But what's this about having hair and a sexual life? Am I missing something here...?)