TSUMUGU · TOCFL C1 (est.) · 字
宇
宇 ＝ 宀 ＋ 于
ㄩˇ · yǔ
noun — eaves, dwelling; space, the cosmos
字源 FORM — what the parts do
宀義a roof
Tyú → yǔ — only the tone shifts
A roof (宀) over 于, which carries the sound — yú with the tone risen to third. From the eaves of a house, the graph reaches out to all of space: 屋宇、宇宙.
故事 STORY — a scene to remember it by
屋簷（宀）一路伸出去，伸到天地的邊——那就是宇。
The eaves (宀) reach outward and keep reaching, to the edge of all space — that is 宇.
字源記憶法
意 · Meanings
(本義)屋宇— eaves, dwelling
→宇宙— the cosmos, space常用
⇒宇航— spaceflight
(本義) original meaning · → ⇒ each arrow = one more step of extension