What is the origin of the word gyp or gip as in my knee is giving me gip today It means pain or discomfort but where does it come from?

Per the Free Online Dictionary at the following URL:

http://www.thefreedictionary.com/gyp


gyp or gip Noun
give someone gyp Brit, Austral & NZ slang to cause someone severe pain: her back's still giving her gyp [probably a contraction of gee up!] Collins Essential English Dictionary 2nd Edition 2006 © HarperCollins Publishers 2004, 2006