Short sword

A short sword, (or shortsword), was a light, piercing melee weapon.

Description
In essence, this weapon was a smaller version of the longsword, but was longer than a dagger or dirk. It possessed many of the same parts, such as a generally double-edged blade, cross-guard, grip, and pommel. The blade was typically long with a sharp point.

Weaponology
Short swords were standard issue for many different types of soldiers. Archers favored this weapon for use when combat range narrowed to a point such that their bows were no longer effective. Many warriors, including fighters, barbarians, paladins, and rangers carried these as a secondary weapon for use in the off-hand.

Smaller races would often use short swords as their primary weapon. Light and maneuverable, yet able to provide many different types of attacks, it was arguably the most common weapon on the battlefield. They were light enough to be used with finesse, but their its smaller size meant they were less deadly than a heavier blade.

Realmslore
These blades were common throughout all parts of Toril, including but not limited to Faerûn, Kara-Tur, and Zakhara. As usual, depending upon what part of Toril you're standing in, they are known by different colloquial names. In Faerûn in addition to being known as a short sword you may also hear the terms gladius or warsword.

Varieties

 * Butterfly sword
 * Katzbalger, also known as "cat gutter", was a type of short and thick sword from the Blade Kingdoms, sometimes carried by Blade Captain and hippogriff cavalry.
 * Wakizashi, a slightly arched shortsword commonly used in Kara-Tur.

Notable short swords

 * Ilbratha : Azoun I's short sword, lost in 389 DR.
 * Shadowflash: The short sword of Vhaeraun.