| 1661 | A Guide To Remembering Japanese Characters (Kenneth G. Henshall) |
| 1756 | A New Dictionary of Kanji Usage |
| 2546 | Classic Nelson (Andrew Nelson) |
| 1468 | Japanese Kanji Flashcards (Max Hodges and Tomoko Okazaki) |
| 821 | Japanese Names (P.G. O’Neill) |
| 1301 | Kanji and Kana (Spahn and Hadamitzky) |
| 1380 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 1844 | Kanji in Context (Nishiguchi and Kono) |
| 1191 | Kodansha Compact Kanji Guide |
| 455 | Kodansha Kanji Dictionary (Jack Halpern) |
| 280 | Kodansha Kanji Learner’s Dictionary (Jack Halpern) |
| 340 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 183 | Les Kanjis dans la tete (Yves Maniette) |
| 17386 | Morohashi |
| 380 | New Japanese English Character Dictionary (Jack Halpern) |
| 3125 | New Nelson (John Haig) |
| 181 | Remembering The Kanji (James Heisig) |
| 193 | Remembering The Kanji, 6th edition (James Heisig) |
| 1276 | Tuttle Kanji Cards (Alexander Kask) |
Jōyō kanji, taught in junior high
JLPT level N1
1618 of 2500 most used kanji in newspapers
Stroke order
On reading compounds
- 洞 【ドウ】 sinus, cavity, antrum, neighborhood (administrative division in North Korea)
- 洞察 【ドウサツ】 discernment, insight
- 空洞 【クウドウ】 cavity, hollow, cave, cavern, hollow
- 風洞 【フウドウ】 wind tunnel
Kun reading compounds
- 洞 【ほら】 hollow, cavity, hole, cave
- 洞穴 【ほらあな】 cave, cavern, den, grotto
Readings
- Japanese names:
- とう
- Korean:
- dong, tong
Spanish
- cavidad
- hueco
- excavación
- prever
Portuguese
- gruta
- caverna
- escavação
French
- antre
- grotte
- excavation
| 349 | 2001 Kanji |
| 3a6.25 | The Kanji Dictionary |
| 1-3-6 | SKIP code |
| 3712.0 | Four corner code |
| 1-38-22 | JIS X 0208-1997 kuten code |
| 6d1e | Unicode hex code |
Jōyō kanji, taught in grade 2
JLPT level N2
805 of 2500 most used kanji in newspapers
Stroke order
On reading compounds
- 角 【カク】 angle, square, cube, bishop, third degree (of the Japanese and Chinese pentatonic scale), Chinese "horn" constellation (one of the 28 mansions), jiao (monetary unit of China; one-tenth of a yuan)
- 角界 【カクカイ】 the world of sumo
- 内角 【ナイカク】 interior angle, internal angle, inside corner
- 外角 【ガイカク】 external angle, exterior angle, outside corner
Kun reading compounds
- 角 【かど】 corner, edge, (street) corner, turning, rough edges (of one's character, words, etc.), abrasiveness, harshness, sharpness
- 角地 【かどち】 corner lot
- 四つ角 【よつかど】 four corners, crossroads, intersecting street, street corner
- 塩角 【しおかど】 sharp taste of (refined) salt
- 角 【つの】 horn, antler, antenna, feeler, tentacle (e.g. of a snail), horn-like projection (e.g. peaks of whipped cream)
- 角隠し 【つのかくし】 bride's head-dress
- 枝角 【えだづの】 antler
- 豊穣の角 【ほうじょうのつの】 cornucopia, horn of plenty
Readings
- Japanese names:
- い、 す、 すみ、 ずみ、 ふさ
- Korean:
- gag
Spanish
- ángulo
- esquina
- cuadrado
- cuerno
Portuguese
- ângulo
- canto
- chifre
French
- angle
- coin
- carré
- corne
- bois (andouillers)
| 173 | A Guide To Reading and Writing Japanese (Florence Sakade) |
| 97 | A Guide To Reading and Writing Japanese 3rd edition (Henshall, Seeley and De Groot) |
| 243 | A Guide To Remembering Japanese Characters (Kenneth G. Henshall) |
| 714 | A New Dictionary of Kanji Usage |
| 4301 | Classic Nelson (Andrew Nelson) |
| 273 | Essential Kanji (P.G. O’Neill) |
| 891 | Japanese Kanji Flashcards (Max Hodges and Tomoko Okazaki) |
| 547 | Japanese Names (P.G. O’Neill) |
| 473 | Kanji and Kana (Spahn and Hadamitzky) |
| 481 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 716 | Kanji in Context (Nishiguchi and Kono) |
| 1650 | Kodansha Compact Kanji Guide |
| 2541 | Kodansha Kanji Dictionary (Jack Halpern) |
| 1293 | Kodansha Kanji Learner’s Dictionary (Jack Halpern) |
| 1761 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 1829 | Les Kanjis dans la tete (Yves Maniette) |
| 35003 | Morohashi |
| 2047 | New Japanese English Character Dictionary (Jack Halpern) |
| 5543 | New Nelson (John Haig) |
| 1812 | Remembering The Kanji (James Heisig) |
| 1953 | Remembering The Kanji, 6th edition (James Heisig) |
| 138 | Tuttle Kanji Cards (Alexander Kask) |
| 2545 | 2001 Kanji |
| 2n5.1 | The Kanji Dictionary |
| 2-2-5 | SKIP code |
| 3-4-3 | SKIP code |
| 2722.7 | Four corner code |
| 1-19-49 | JIS X 0208-1997 kuten code |
| 89d2 | Unicode hex code |