Meito

A Meito is not a type of sword but rather the status of a sword.

In Japan, this means the sword has a history and is of legendary status. The blade is normally a quality blade which stands out above all other swords in its endurance and sharpness.

A Meito is sometimes associated with the warrior who wields it and becomes part of his identity. Regardless of who owns them a Meito is regarded with highest respect in Japan and to be given a Meito is to carry a great honour alongside it. Often warriors who lost in battle would have their Meito taken from them by the victor, thus loosing their honour alongside it as to loose a Meito is to disrespect the honour of wielding it.

To wield a Meito honourably, usually it would be passed down to them from master to pupil or from another family member. There exist several other methods alongside this which are acceptable but uncommon. Another method of gaining a Meito honourably was to be offered it, this was usually out as show of respect from one person to another. A warrior may also win it in battle against another warrior in a fair duel and thus be allowed to claim it as their own.

To steal a Meito or gain it using another dishonorable action is to show the Meito disrespect and warriors who do so were often frowned upon. To put the status of a Meito in a western style of thinking, a Meito to would be considered in status on par with swords like Excalibur.

One Piece
In anime, Meito is often added to part of the name of a sword in error by those who do not understand that Meito is a status. In One Piece, an example would be Zoro's Shuusui which is often recorded by fans as "Meito Shuusui" instead of just "Shuusui".

Tashigi's dream is to free all the Meito from the hands of villains such as pirates. She believes the swords are crying because instead of being used for noble and honourable deeds, they are being used for criminal use. Her reason for tracking Zoro is to gain ownership of his Meito, the Wadō Ichimonji which she believes is in the hands of a bad person. Wadō Ichimonji was the Kuina's family Meito and Zoro was allowed permission to wield it as part of their promise to each other and carry to with it her dreams.

Ryuuma's Meito was his sword Shuusui which belongs to Zoro now. Upon defeat, Brook's shadow offered it to Zoro as a sign of honor for their battle and because he shamed the Samurai it inhabited by losing to Zoro.