A bat'leth (Klingon: "sword of honor") is a crescent-shaped metal blade about 116 centimeters across. The weapon holds significance in the Klingon religion that revolves around the exploits of Kahless, who was said to have forged the first Bat'leth from a lock of his hair. Remarkably, in an age of spacecraft and energy weapons, many Klingons carry a bat'leth into battle, affirming the "space viking" cliché that they came to epitomize.
Even when compared to real-world melee weapons, the bat'leth is a poor weapon. It gives very little reach compared to swords, axes, and spears; it has nothing to protect the hands of the wielder from harm; and it is of course very large and heavy. Its only advantage is that it is good for parrying off blows.
- DS9 "Way of the Warrior"