A fighting knife has a blade designed to most effectively inflict injury in close-quarters physical confrontations. The combat knife and the trench knife are examples of military fighting knives.
An assortment of fighting knives
Top: Bowie Knife c. 1850s Bottom: Naval Bowie Knife c. 1860s
M1918 Trench Knife
U.S. Marine KA-BAR Knife
A combat knife is a fighting knife designed for military use and primarily intended for hand-to-hand or close combat fighting.
Soviet NR 43 Combat Knife
"KA-BAR" USMC Combat Knife, the standard U.S. Marine Corps combat knife during and after World War II
A modern KM2000 of the German Army
Glock Feldmesser FM 78 and its sheath