sword, saber, knife
刀 centers on a single-edged cutting blade: a sword, saber, or knife. The core idea is a sharp tool or weapon used for cutting.
刀 is a pictograph of a single-edged blade with a curved back and a handle. The modern two-stroke form preserves the basic blade shape.
The curved vertical stroke is the blade, and the short horizontal stroke is the handle. Picture a simple knife or sword: 刀.
For トウ, imagine a sword with a toe-shaped guard: toe -> トウ, and the blade extends from it.
sword (esp. Japanese single-edged); katana
sword; dagger; knife; bayonet
long sword (as opposed to the shorter katana)
razor
Pacific saury (Cololabis saira); mackerel pike
crossing swords
liking both alcohol and sweets; person who likes both liquor and sweets
drawing a sword; drawn sword
short sword; knife; dagger; dirk; tantō
performing a surgical operation
bamboo sword (for kendo); bamboo fencing stick
naginata; polearm with a curved single-edged blade (similar to a glaive)
wooden sword
cutting in two with a single stroke
bewitched sword; magical sword; demon sword
assistance (in a fight); help; aid; backup
knife blade; sword blade
famous sword; excellent sword
treasured sword
hand used like a sword in striking