| 凹 | āo | concave / depressed / sunken / indented / female (connector etc) | ![]() |
| 凹入 | āo rù | recessed / concave | ![]() |
| 凹进 | āo jìn | concave / recessed / dented | ![]() |
| 凹凸 | āo tū | concave or convex / bumps and holes / uneven (surface) / rugged | ![]() |
| 反光镜 | fǎn guāng jìng | reflector (typically concave, as in a torch) / mirror (typically plane or convex) | ![]() |
| 凹透镜 | āo tòu jìng | concave lens | ![]() |
| 瓴 | líng | concave channels of tiling | ![]() |
| 凹坑 | āo kēng | concave depression / crater | ![]() |
| 凹岸 | āo àn | concave bank | ![]() |
| 凹面镜 | āo miàn jìng | concave mirror | ![]() |
| 斜钩 | xié gōu | (downwards-right concave hooked character stroke) | ![]() |
| 凹镜 | āo jìng | concave mirror | ![]() |
| 回光镜 | huí guāng jìng | concave reflector (e.g. in spotlight) | ![]() |
| 凹形海岸线 | āo xíng hǎi àn xiàn | recessing coastline / recessive coastline / concave coastline | ![]() |
