Twin swords are commonly referred to as "pair of swords" or "sword pair." This term is used to describe a set of two swords that are similar in design, length, and purpose. The concept of twin swords often involves wielding one sword in each hand simultaneously, allowing for dual-wielding techniques in combat.

In specific cultural contexts, twin swords may have distinct names. For example:

1. Katana and Wakizashi: In Japanese swordsmanship, the combination of a katana (a long sword) and a wakizashi (a shorter companion sword) is known as "daisho." The daisho was traditionally worn by samurai as a symbol of their social status and proficiency in combat.
2. Sai and Kama: In Okinawan martial arts, a pair of sai (metal truncheon-like weapons) or kama (sickles) can be used as twin weapons. They are often employed together in intricate and fast-paced techniques.
3. Dao and Jian: In Chinese martial arts, a pair of dao (single-edged sabers) or jian (double-edged straight swords) can be wielded as twin swords. This technique is often seen in various styles of Chinese martial arts forms.

It's important to note that the term "twin swords" or "pair of swords" can encompass different types of swords used together as a matched set, depending on the specific cultural and historical context.