TSUMUGU · TOCFL 1 · 字
睡
ㄕㄨㄟˋ · shuì
verb — to sleep
字源 FORM — what the parts do
{zh,ch,sh}ITchuí → shuì — ch to sh inside the family
An eye (目) drooping (垂) — the lids come down. The first sense is dozing where one sits; later, all sleep: 睡覺、睡著. 垂 chuí doubles as the sound, ch worn to sh.
故事 STORY — a scene to remember it by
眼皮（目）越來越重，一垂（垂）下來，人坐著就睡著了。
The lids (目) grow heavy, droop (垂) once — and he is asleep sitting up.
字源記憶法
意 · Meanings
(本義)坐寐— dozing off where one sits
→睡覺、睡著— to sleep常用
⇒午睡— the noon nap
(本義) original meaning · → ⇒ each arrow = one more step of extension