English Noun zombie knife (plural zombie knives) (UK) A knife decorated with images or words suggesting that it is to be used to commit violence. (UK law) The street name given to a knife, which is over eight-inches in length and often has a serrated edge, spikes or more than two sharp points.[1] References [1]United Kingdom - Home Office Further reading zombie knife on Wikipedia.Wikipedia Wikiwand - on Seamless Wikipedia browsing. On steroids.