A man who rapes or beats his nephews and nieces or other children, or treats children like dirt. Originally a character from the book Once Were Warriors by Alan Duff, which was also made into a movie.

A man who asked 5 boys in his care to call him "Uncle Bully" was recently arrested for assault.
You're no better than Uncle Bully, I should cut your dick off!
by Bloopy April 10, 2005
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