TSUMUGU · TOCFL 2 (est.) · 字
須
須 ＝ 彡 ＋ 頁
ㄒㄩ · xū
verb — must, have to
字源 FORM — what the parts do
彡義strands of hair
Hair (彡) on a face (頁) — the beard, the old graph of 鬚. The word must borrowed the bearded character; the whiskers added 髟 on top and moved into 鬚. What remains of 須 is the obligation: 必須、無須.
故事 STORY — a scene to remember it by
下巴三綹鬍鬚（彡），順著臉（頁）一直垂到衣領。
Three strands of beard (彡) run down the face (頁), all the way to the collar.
字源記憶法
意 · Meanings
(本義)鬍鬚（鬚的本字）— the beard — the old form of 鬚
(假借)必須、須要— must, have to常用
(本義) original meaning · → ⇒ each arrow = one more step of extension
關 · Related
順＝ ＋ 川shùnthe lookalike — 順 runs a river 川 past the head, 須 brushes hair on it鬚xūthe beard reclaimed — long hair 髟 added on top