Dachi may refer to:
An ōdachi (大太刀) (large/great sword) or nodachi (野太刀, field sword) was a type of traditionally made Japanese sword (nihonto) used by the samurai class of feudal Japan. The Chinese equivalent and 'cousin' for this type of sword in terms of weight and length is the Miao dao, and the Western battlefield equivalent (though less similar) is the Spanish Espada Bastarda or Scottish Claymore.
The character for ō (大) means "big" or "great". The dachi here (太刀) is the same as tachi (太刀, lit. "great sword"), the older style of sword/mounts that predate the katana. The chi is also the same character as katana (刀) and the tō in nihontō (日本刀 "Japanese sword"), originally from the Chinese character for a blade,dāo.
To qualify as an ōdachi, the sword in question would have a blade length of around 3 shaku (35.79 inches or 90.91 cm); however, as with most terms in Japanese sword arts, there is no exact definition of the size of an ōdachi.
Practically speaking, the function/use of most ōdachi fall into the first two categories—as ceremonial objects and cavalry swords. The possible functions of the ōdachi can be categorized as follows:
Yuku ate nado nai mayonaka yobidashita no wa
Koi wo shite 'ru ano musume ja naku omae wo datta yo
Sonna hen na yoru mo tama ni wa ii ja nee ka to
Nani mo iwazu WOW Arukidashita
Wakaranai itsu mo ore-tachi
Sakaratte toomawari bakari
Kakko warui yatsu sa Demo ichido datte uso wa tsuichai nai hazu sa
Kakko tsukete bakari demo suppadaka no kono kokoro wa kizudarake sa
Kanau hazu mo nai yume dake oikakete 'ru
Bakayarou sa Ore-tachi nara dou ni mo naranee
Da kedo itsu ka kitto deau hazu no desutinii
Tamashii kogashi WOW naguritsukeru
Mayowanai itsu mo ore-tachi
Korogatte massugu ni susumu
Mono-wakari ga warui kedo shinji-tsuzuketakute zutto damatte 'ru
Kuchi nanka dasanai kedo yuujou nante iu serifu terekusai ze
Kakko warui yatsu sa Demo ichido datte uso wa tsuichai nai hazu sa
Kakko tsukete bakari demo suppadaka no kono kokoro wa kizudarake sa
Mono-wakari ga warui kedo shinji-tsuzuketakute zutto damatte 'ru
Yuujou nante iu serifu terekusai ze