stopping power

Short definition from Wiktionary

Noun

1. 1
   The ability of a weapon (typically a firearm or other ranged weapon) to rapidly incapacitate or immobilize a target.
2. 2
   A research measure that captures a print advertisement's ability to grab the attention of the reader; also known as the attention rating.
3. 3
   The retarding force exerted on a high-energy particle by interactions with the medium through which it passes.