Ballistic knife

Knife with ejectable blade

A ballistic knife is a knife with a detachable blade that can be ejected to a distance of several meters/yards by pressing a trigger or operating a lever or switch on the handle. Spring-powered ballistic knives first appeared in books and press reports on Soviet and Eastern Bloc armed forces in the late 1970s. Commercially-produced ballistic knives briefly gained notoriety in the United States in the mid-1980s after they were marketed and sold in the United States and other Western countries. Since then, the marketing and sale of ballistic knives to civilians has been restricted or prohibited by law in several nations.

This keyword could refer to multiple things. Here are some suggestions: