A portmanteau of "make shift" and "knife" (or "knives"), used to describe a homemade weapon made up of objects one would find in a prison that is not metallic.
a home-made weapon used for CUTTING, not stabbing. a sharpened tooth-brush is not a shiv, that is a shank, which is used for stabbing.
guy 1:"i got cornered on my last day in prison, i was lucky i had my shiv!"
guy 2:"oh sweet! im going to jail soon, how do you make one?"
guy 1:"take a razor blade and a lighter in with you, then melt the blade to your toothbrush."
Shiv is a person that can be suicidal and shit after someone precious to him leaves him but in the end he is fine, he is mostly a pretty goofy but good friend, he can be serious at times but keeps the fun wherever you go, he won’t chat with his family members as much as he does with friends, he likes to play games and socialise, he also is a ambivert. Plus he after some while respects you for whatever you are. He can be a good ladies man, he can 😏