A sword, especially a Japanese single-edged sword (katana).
侍は腰に刀を差して町を歩いた。
The samurai walked through town with a sword at his waist.
その美術館には鎌倉時代の刀が展示されている。
The museum displays a katana from the Kamakura period.
彼は刀の手入れを毎週欠かさない。
He never misses cleaning his sword every week.
A scalpel — a small surgical knife used in operations.
手術では滅菌した刀を使って切開を行った。
In the surgery, a sterilized scalpel was used to make the incision.
研修医は初めて刀を握って緊張していた。
The trainee doctor was nervous when he held a scalpel for the first time.
A chisel, burin, or graver — a tool used for carving or engraving.
木彫りの細かい部分は彫刻刀で仕上げる。
The fine details of the woodcarving are finished with a chisel.
彫刻刀の刃が欠けていたので研いだ。
The chisel's blade was chipped, so I sharpened it.
Knife money — knife-shaped commodity money used in ancient China.
博物館には戦国時代の刀銭（刀形の貨幣）が展示されている。
The museum displays knife money (knife-shaped currency) from the Warring States period.