Green’s Dictionary of Slang

(S.Afr. Und.) a new inmate, a fool, one who has not yet learned how to cope with prison conditions.

1981		N. Haysom Social Justice Resource Project Appendix: 🌐 Victim was a Mpata who had reported the theft of his soap. Witness killed during the trial.
2008		book review at web.uct.ac.za 🌐 For the reader who has not grown up in a black or coloured neighbourhood somewhere in South Africa and has never heard terms like ndota (old gangster or vuil mpata (uninitiated prisoner) [etc.].