1. A homemade knife, sometimes very crudely made from ordinary objects (sharpened end of a toothbrush), fashioned from various materials i.e. steel, glass, plastics, woods, etc. It can be made into multiple sizes and styles such as a serated or smooth blade. Found and used in prisons.
"Hand me that shank,ese! I'm gonna punch this fools ticket if it's the last thing I do!"