1. Kanji Breakdown: 宇
Meaning: Eaves of a roof; universe; space.
Reading:
Onyomi (Sino-Japanese reading): ウ (u)
Kunyomi (Native Japanese reading): None in common modern use.
The kanji is a compound ideograph (会意文字). It consists of two parts:
Top (宀): The "roof" radical (うかんむり), representing a house or shelter.
Bottom (于): A phonetic component that provides the sound ("u"), but also carries a meaning of "expanding" or "reaching."
The core concept is the "eaves of a roof that extend outwards, encompassing the space beneath them." This imagery of a roof covering and defining a space naturally expanded to mean the entire "cosmos" or "universe"—the ultimate "roof" over everything. It also relates to the concept of "space" in a more abstract sense.
2. Stroke Order and Writing (6 Strokes)
Correct stroke order is essential for balanced and legible kanji.
Stroke Order Diagram:
Start with the top radical "宀" (roof radical):
Then, write the bottom part "于":
Key Writing Tips:
Write from top to bottom.
The "宀" radical should be wide enough to "shelter" the components below.
The bottom part "于" is centered. The final vertical hook (はね) is distinctive.
The overall character should feel stable and encompassing.
3. Core Meanings & Example Sentences
Here are the primary meanings of "宇" with common vocabulary and practical example sentences.
A. Universe / Cosmos (う)
宇宙 (うちゅう, uchū)
Meaning: Universe, cosmos, space.
Example: 宇宙には無数の星があります。
English: There are countless stars in the universe.
宇宙飛行士 (うちゅうひこうし, uchū hikōshi)
Meaning: Astronaut.
Example: 子供の頃、宇宙飛行士になるのが夢でした。
English: When I was a child, I dreamed of becoming an astronaut.
B. Eaves / Roof (This meaning is almost exclusively used in the compound word below)
屋宇 (おくう, okuu)
Meaning: Houses and buildings (a formal/literary term).
Example: (Literary context) この地に屋宇を構える。
English: (Literary) To build a house on this land.
C. In Names (Personal and Brand)
宇 (たかし, Takashi)
Meaning: A common element in male given names, carrying a grand, cosmic connotation.
Example: 私の兄の名前は雄宇です。
English: My older brother's name is Yū.
Summary
Kanji: 宇
Core Meaning: Eaves, Roof; Universe, Cosmos.
Keyword: Encompassing Space.
Readings: On'yomi ウ (u)
Stroke Order: 6 strokes. Structure: 宀 (roof) + 于 (phonetic/expanding).
This character beautifully illustrates how a concrete concept (eaves) can expand into an abstract, grand one (the universe). While its root meaning is architectural, its primary modern usage is in the word 宇宙 (uchū) for "universe" or "space." It is also a popular component in names, implying breadth and grandeur.