http://mabufs.i2p/goon-fu/shinobi-jutsu
The noun "shinobi," formed from the verb "shinobu," means: 1) secret infiltrator; 2) a spy, a spy, a spy; 3) theft. The word "ninja" did not appear until the twentieth century. Previously, its equivalent was a different reading of the same characters: "shinobi-no-mo", literally, "a man in hiding", "a man who infiltrates secretly".