Etymology

Originally used as a general term for single-edged sword having a "sori" or curvature of the blade. While the "sugata" or form can take many shapes, including double edged, the term is now used incorrectly to describe nihontō that are 2 shaku (606 mm / 24 in) and longer, also known as "dai" or "daito" among Western sword lovers.

This distinguishes them from the chokutō, which feature straight blades and were imported from China and Korea via trading. The chokutō is speculated to have been the first "sugata" type the katana took on, being modeled after the imported swords. This emergence of the first nihontō took place the same time period as the beginning of Japanese fuedalism and recognition of the daimyo or "great family" in the late nineth century.

Pronounced kah-ta-nah, the kun'yomi (Japanese reading) of the kanji 刀, the word has been adopted as a loanword by the Portuguese language from which it was adopted by other European languages. As Japanese does not have separate plural and singular forms, both "katanas" and "katana" are considered acceptable forms in English.^{[citation needed]}

Another term, Daikatana (usually given as the kanji 大刀), is a pseudo-Japanese term meaning "large sword". (In Japanese, 大刀 is actually read daitō. ^[2]) The reading mistake comes from the different ways Japanese Kanji can be read, depending on their combination or not in a word. It has been used in some (English-language) fictional works to represent a kind of large katana (perhaps better known as an ōtachi); the video game Daikatana, for example used this pseudo-term as its title. The correct name of this type of weapon is Tachi, and is different from ōtachi and Nodachi.