TSUMUGU · TOCFL 2 (est.) · 字
約
約 ＝ 糸 ＋ 勺
ㄩㄝ · yuē
verb — to arrange, make an appointment; to bind, restrain; adv — approximately
字源 FORM — what the parts do
糸義silk thread, a cord
勺聲sháo — gives the sound, worn from sh to ya ladle — borrowed for its sound
ITsháo → yuē — the initial and tone both shift
Silk cord (糸) and 勺 sháo for the sound — a ladle, lent only for how it reads, its sh later worn to y. The core act is binding with a cord: from tying-up come the things two sides tie themselves to — 約定、契約、約會 — and the loose "about" of an approximate amount.
故事 STORY — a scene to remember it by
一條繩子（糸）把兩頭綁在一起——說定了，誰都不能反悔。
A cord (糸) ties the two ends together — it is settled, neither side can pull free.
字源記憶法
意 · Meanings
(本義)約束、纏束— to bind, restrain
→約定、契約— to arrange; an agreement常用
⇒約會— a date, appointment常用
⇒大約、約有— about, approximately常用
(本義) original meaning · → ⇒ each arrow = one more step of extension