| 1032 | A Guide To Remembering Japanese Characters (Kenneth G. Henshall) |
| 1920 | A New Dictionary of Kanji Usage |
| 664 | Classic Nelson (Andrew Nelson) |
| 1883 | Essential Kanji (P.G. O’Neill) |
| 1087 | Japanese Kanji Flashcards (Max Hodges and Tomoko Okazaki) |
| 1893 | Kanji and Kana (Spahn and Hadamitzky) |
| 2069 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 1922 | Kanji in Context (Nishiguchi and Kono) |
| 173 | Kodansha Compact Kanji Guide |
| 4294 | Kodansha Kanji Dictionary (Jack Halpern) |
| 2170 | Kodansha Kanji Learner’s Dictionary (Jack Halpern) |
| 2924 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 33 | Les Kanjis dans la tete (Yves Maniette) |
| 1810 | Morohashi |
| 3482 | New Japanese English Character Dictionary (Jack Halpern) |
| 444 | New Nelson (John Haig) |
| 33 | Remembering The Kanji (James Heisig) |
| 33 | Remembering The Kanji, 6th edition (James Heisig) |
| 1039 | Tuttle Kanji Cards (Alexander Kask) |
凹
Jōyō kanji, taught in junior high
JLPT level N1
2206 of 2500 most used kanji in newspapers
Stroke order
On reading compounds
- 凹 【オウ】 concave, hollow, sunken
- 凹凸 【オウトツ】 unevenness, bumpiness, roughness, ruggedness, imbalance, inequality, unevenness, disparity
- 肋凹 【ロクオウ】 costal fovea
Kun reading compounds
- 窪む 【くぼむ】 to cave in, to become depressed, to sink
- 凹む 【へこむ】 to be dented, to be indented, to yield, to give, to sink, to collapse, to cave in, to be beaten, to be overwhelmed, to yield, to give in, to give up, to be disheartened, to feel down, to feel depressed, to suffer a loss, to lose
- 発達凸凹 【はったつでこぼこ】 developmental irregularities, developmental disorder, neurodiversity
- 穴ぼこ 【あなぼこ】 hole, hollow, pothole (road, pavement, etc.)
Readings
- Korean:
- yo
Spanish
- hueco
- cóncavo
- hundido
Portuguese
- côncavo
- concavidade
- afundado
French
- concave
- creux
- dépression
| 3675 | 2001 Kanji |
| 0a5.14 | The Kanji Dictionary |
| 4-5-1 | SKIP code |
| 4-6-1 | SKIP code |
| 4-4-1 | SKIP code |
| 7777.0 | Four corner code |
| 1-17-90 | JIS X 0208-1997 kuten code |
| 51f9 | Unicode hex code |