noun
long sword; tachi
General term for a long sword, often contrasted with the shorter katana. In modern contexts, may refer to any long Japanese sword.
博物館で古い太刀を見た。
I saw an old long sword at the museum.
noun
tachi; sabre-like sword
Only when written 太刀
Historical term for a specific type of Japanese sword worn slung from the hip with the cutting edge facing down, used primarily before the katana became common.
平安時代の武士は太刀を腰に佩いていた。
Warriors of the Heian period wore tachi at their hips.
Rarely used kanji form.
The reading たち is native Japanese. The kanji 太刀 literally means 'thick sword', referring to its larger size compared to a katana.