A double-edged katana refers to a variation of the traditional Japanese sword, the katana, that features a blade with two cutting edges. The standard katana typically has a single cutting edge, but a double-edged katana has cutting edges on both sides of the blade.

The term "double-edged katana" is somewhat of a misnomer because the true katana design traditionally features a single-edged blade. The single edge of a katana is typically sharpened and used for cutting, while the backside of the blade, called the "mune," is not sharpened.

However, there have been instances where swords were produced with blades that had two sharpened edges, similar to a double-edged sword. These swords were often called "ken" or "uchigatana" rather than katana. The term "uchigatana" is sometimes used to describe the earlier form of the sword that was used primarily for fighting on foot.

It's important to note that the design and terminology of Japanese swords can be complex, and variations exist throughout history. While a double-edged katana may not be a traditional or common form, variations and regional differences in sword designs can sometimes result in swords that deviate from the standard single-edged katana configuration.