The falchion is a sword closely resembles a modern machete, or in some cases, a giant bowie knife. It is short (overall length 35"), heavy, and single edged. Typically the blade is widest near the tip, providing a more powerful blow.
The falchion was used from the 12th through the 16th centuries. It was originally developed as a sort of edged club for use against chain mail armor. While mail was difficult to cut, a falchion would inflict crushing wounds on a mail-clad opponent even if it did not cut through their armor.
The most famous example of this type is the Conyers Falchion, which rests in the Treasury of Durham Cathedral in England. It dates from the 12th century and is said to have been used by Sir John Conyers when he slew the Sockburn Wyrm, a dragon which had been terrorizing the local folk in Durham. This story served as the inspiration for Lewis Carroll's poem Jabberwocky