from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adjective of or relating to the bore of a gun (or its ammunition) that measures forty-five hundredths of an inch in diameter
Sorry, no etymologies found.
The .45-calibre semi-automatic pistol was designed by Browning, who was born in Utah in 1855, to fill the US military's need for a pistol with stopping power - the ability to fell an enemy with a single shot.