凹

• Pinyin: āo
• Hanzi breakdown: 凹 = pictograph of a concave shape

Meaning

Concave; sunken; indented.

Describes surfaces that curve inward or are recessed. The opposite of 凸 (convex). Used in technical, descriptive, and everyday contexts.

Examples

1. 这面凹镜可以把光线聚焦到一点。 This concave mirror can focus light to a single point.
2. 地上有一个凹坑，走路要小心。 There's a pit in the ground — be careful when walking.
3. 他的脸颊凹进去了，看起来很消瘦。 His cheeks have sunken in — he looks very thin.

Usage Guide

Context: descriptive, technical

Tone: objective

Do Say

• 凹凸不平的路面很难走。(Uneven road surfaces are hard to walk on.)
• 这里有一处凹陷。(There's an indentation here.)

Don't Say

• 把'凹'读成āo之外的读音 (Don't mispronounce 凹 — it's āo, not wā)

Origin & History

A pictographic character depicting a concave shape — the middle part is lower than the sides.

Cultural Context

Generation: All ages

Social background: Universal