Language: Mandarin Chinese
Source: In common use
Jiàn (劍) is the name for the Chinese straightsword, from a large two-handed version to a standard size, up to shortswords and daggers. The defining feature of the jiàn is not only that it's double-edged, but that both edges are exactly the same length. Therefore, a straight sword with a single long edge and double-edged tip section would still be considered a dāo, even if the tip section is completely symmetrical.
A good jian of the late Qing.
A Ming dynasty jian
The jiàn was the sidearm of the Chinese literati. Their blades relatively wide and heavy compared to straightswords of other cultures, and as such has both good thrusting and cutting abilities.
Types of jian
We make a distinction between several types of jiàn:
Duǎnjiàn (短劍) or "short sword"
Used to describe short jiàn.
Chángjiàn (長劍) or "long sword"
Usually used to describe jiàn between 80-105 cm long.
Shuāngshǒujiàn (雙手劍) or "double handed sword"
Long jiàn with a large grip meant for two-handed use. Antique shuāngshǒujiàn can be anywhere from 110 cm to 160 cm long.
Shuāngjiàn (雙劍) or "double jian"
Two jiàn that fit in a single scabbard. Usually, the hilts are flat on one side to fit in the scabbard side-by-side. Many duǎnjiàn are of this type, full-length double jiàn are somewhat rarer.
A pair of very good, short shuangjian of the first half of the 19th century.
Tuánliàn jiàn (團練劍) or "militia jian"
Utilitarian jiàn made for rural militia that used them to defend their villages. Most of them are fairly short, stout and heavy. Full-length tuánliàn jiàn are rarer but encountered from time to time.
A tuánliàn jiàn from my own collection.