bench, stool
櫈 centers on a piece of furniture for sitting: a bench or stool, typically made of wood.
櫈 combines 木 (wood) with 凳 (stool, bench), forming a phono-semantic compound where 木 indicates the material and 凳 suggests the meaning and possibly the sound.
The left side 木 is wood, and the right side 凳 looks like a low table or seat. Picture a wooden bench made from a plank and legs: 櫈 is a wooden stool.
For トウ, imagine a toe-tapping person sitting on a wooden stool: toe -> トウ, and the stool is made of wood.