Odachi (big sword) or Nodachi (field sword) was a big anti-cavalry sword (a big traditional Japanese sword called nihonto) which was originally used on the battlefield to knock down the enemy's horse and the enemy. Later, it was also used by horsemen and infantry in hand-to-hand combat. The blade was about 150 cm long, so it was not possible to pull the sword out of the sheath on the waist, so it was carried on the back or carried by samurai servants.
