Kanji Breakdown: 勾
Core Meaning: Hook, bend, curve; ratio/proportion
Reading: コウ (kō)
Structure Analysis:
勹 (wrapping radical): enclosure/bend
厶 (private): phonetic component
Character visually represents "curved/hooked shape" - depicting bent forms and angular relationships.
Essential Vocabulary & Usage
1. 勾配 (こうばい・kōbai) - Slope, gradient
"This road has a steep slope."
この道は勾配が急だ。
2. 勾留 (こうりゅう・kōryū) - Detention, custody
"The suspect was placed in detention."
容疑者は勾留された。
3. 勾玉 (まがたま・magatama) - Curved jewel (ancient ornament)
"Magatama are traditional curved beads."
勾玉は伝統的な曲玉だ。
4. 勾引 (こういん・kōin) - Subpoena, summons
"He received a court summons."*
彼は勾引状を受け取った。
Key Insight
勾 describes curved geometries and angular relationships - used in mathematics (slopes), law (detention - metaphorically "hooking" someone), and traditional crafts (curved jewels). It's essential for technical fields describing inclines, legal contexts for custody, and cultural heritage like magatama beads.
*Stroke Order: 4 strokes - write wrapping radical first, then complete internal strokes.*