A very long two-handed sword (the name translates exactly from German as zwei = two, and händer = hands, due to the length of the sword's hilt), most commonly used by Landsknecht Doppelsoldners. The zweihänder is usually at least five feet long (1.6m), often longer, weighs between seven and fourteen pounds (2.5-5.0kg), and has either a straight blade, or a flamberge, or undulating blade. They were relatively slim blades, in contrast with their distinct large dimensions. The zweihänder is made to be a slashing weapon rather than a thrusting weapon. These weapons were used primarily for fighting against pike-squares where they would hack paths through lopping the tips off the poles, although there were also schools that used them for single combat.
Zweihänders are also known as bihänders and/or bidenhänder (both of which have the same translation as zweihänder) by German speakers.
Nowadays they can be seen in quite a few role-playing games (usually without the umlaut), notably the Warcraft universe.