凸

• 拼音: tū
• 汉字拆解: 凸 — pictograph of a protruding shape

含义

Convex; protruding; raised; bulging out.

Describes a surface that curves or bulges outward, opposite of concave (凹). Used in optics (凸透镜 convex lens), geography (凸岸 convex bank), and general descriptions of shapes.

例句

1. 凸透镜可以聚焦光线，用来点火或者放大。
2. 地面上有几块凸起的石头，走路要小心。
3. 这款键盘的键帽是凸面设计，手感很舒服。

用法指南

语境: shapes, optics, descriptions

语气: technical

正确说法

• 凸透镜。(Convex lens.)
• 凸起。(Protrusion.)

错误说法

• 把'凸'和'凹'搞混 (凸 is convex/protruding — 凹 is concave/indented; don't confuse them)

起源与历史

Pictograph depicting something protruding upward.

文化背景

世代: All ages

社会背景: Universal