• 中なか — inside / middle
• 真まん中なか — center / dead center
• 水中すいちゅう — underwater
• 午前中ごぜんちゅう — all morning
• 途中とちゅう — on the way / in the middle of
• 中止ちゅうし — suspension / cancellation
• 中国ちゅうごく — China

The kanji “中” originally depicted a vertical line running through a box, symbolizing something at the center. It's a high-frequency character essential for spatial, temporal, and conceptual uses in Japanese — from geography (中国) to mental focus (集中).