Noun - prison term
Refers to a pencil modified in a way to light fires using AC electrical power in a prison cell.
In prisons that have out-lawed smoking, matches are not allowed.
Inmates will generally use a paper-clip bending one sharp end out to poke it through the eraser of a sharp pencil. The other end is pushed into an electrical outlet. A wire from headphones or even rolled aluminum foil is pushed in the other hole in the outlet. When the wire is "struck" up against the sharp graphite carbon of the pencil it produces a "carbon-arc" capable of lighting toilet paper or other combustibles found in a prison cell.
A striker is considered contraband in the prison systems.
Hey, loan me your striker, I wanna smoke a pinner.
You can make tatt-ink with the soot from burning aftershave if you light it with a striker and place it under a paper bag.