A false term used mainly in a court of law or in government owned scientific research into weapons that describes a "weapon" not used to directly kill. Unfortunately/Fortunately, there is no such thing.
Nerd/Government official: This dusty stuff knocks out all of an area's electricity supply, resulting in no deaths. Not one death can be directly attributed to this.
Gumba: *grabs the stuff and stabs the nerd/official through the eye, piecing his brain and killing him*
You can't arrest me, he said it himself. No death will ever be attributed to this weapon.