Cinquedea
The Cinquedea is a straight, very broad bladed knife of Italian origin. The name refers to the blade width, which was supposed to be 5 fingers wide at the hilt. It was normally carried horizontally so that it could be drawn with the left hand from the back or belt; it was designed to use brute force to penetrate gaps in armour plate, with the width of blade giving the weapon its strength.
How to cite this article: Dugdale-Pointon, TDP. (19 April 2004), Cinquedea, http://www.historyofwar.org/articles/weapons_cinquedea.html