| 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 |
Stroke order
On reading compounds
- 窟院 【クツイン】 cave temple
- 巣窟 【ソウクツ】 den, haunt, hangout, nest, lair
- 宝窟 【ホウクツ】 treasure mine
Kun reading compounds
- 岩屋 【いわや】 cavern, grotto
Readings
- Korean:
- gul
Spanish
Portuguese
French
- grotte
- caverne
| 3331 | Classic Nelson (Andrew Nelson) |
| 1943 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 2923 | Kodansha Kanji Dictionary (Jack Halpern) |
| 2032 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 1335 | Les Kanjis dans la tete (Yves Maniette) |
| 25552 | Morohashi |
| 2328 | New Japanese English Character Dictionary (Jack Halpern) |
| 4206 | New Nelson (John Haig) |
| 2615 | Remembering The Kanji (James Heisig) |
| 1420 | Remembering The Kanji, 6th edition (James Heisig) |
| 3m10.6 | The Kanji Dictionary |
| 2-3-10 | SKIP code |
| 2-5-8 | SKIP code |
| 3027.2 | Four corner code |
| 1-23-02 | JIS X 0208-1997 kuten code |
| 7a9f | Unicode hex code |
Jōyō kanji, taught in grade 5
JLPT level N2
329 of 2500 most used kanji in newspapers
Stroke order
On reading compounds
- 比 【ヒ】 ratio, proportion, match, equal, equivalent, comparison, compared with ..., relative to ..., Philippines, explicit comparison (style of the Shi Jing)
- 比較 【ヒカク】 comparison
- 口径比 【コウケイヒ】 aperture ratio (inverse of the f-number), relative aperture
- 正比 【セイヒ】 direct ratio
Kun reading compounds
- 比べる 【くらべる】 to compare, to make a comparison, to compete, to vie
Readings
- Japanese names:
- い、 ぴっ
- Korean:
- bi
Spanish
- comparación
- proporción
- relación
- Filipinas
- comparar
Portuguese
- comparar
- corrida
- razão
- Phillipines
French
- comparer
- compétition
- proportion
- Philippines
| 697 | A Guide To Reading and Writing Japanese (Florence Sakade) |
| 792 | A Guide To Reading and Writing Japanese 3rd edition (Henshall, Seeley and De Groot) |
| 771 | A Guide To Remembering Japanese Characters (Kenneth G. Henshall) |
| 557 | A New Dictionary of Kanji Usage |
| 2470 | Classic Nelson (Andrew Nelson) |
| 589 | Essential Kanji (P.G. O’Neill) |
| 660 | Japanese Kanji Flashcards (Max Hodges and Tomoko Okazaki) |
| 137 | Japanese Names (P.G. O’Neill) |
| 798 | Kanji and Kana (Spahn and Hadamitzky) |
| 812 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 276 | Kanji in Context (Nishiguchi and Kono) |
| 1146 | Kodansha Compact Kanji Guide |
| 29 | Kodansha Kanji Dictionary (Jack Halpern) |
| 14 | Kodansha Kanji Learner’s Dictionary (Jack Halpern) |
| 14 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 456 | Les Kanjis dans la tete (Yves Maniette) |
| 16743 | Morohashi |
| 26 | New Japanese English Character Dictionary (Jack Halpern) |
| 3010 | New Nelson (John Haig) |
| 447 | Remembering The Kanji (James Heisig) |
| 482 | Remembering The Kanji, 6th edition (James Heisig) |
| 450 | The Kanji Way to Japanese Language Power (Dale Crowley) |
| 643 | Tuttle Kanji Cards (Alexander Kask) |
| 1256 | 2001 Kanji |
| 2m3.5 | The Kanji Dictionary |
| 1-2-2 | SKIP code |
| 1-3-2 | SKIP code |
| 2171.0 | Four corner code |
| 2111.0 | Four corner code |
| 1-40-70 | JIS X 0208-1997 kuten code |
| 6bd4 | Unicode hex code |
Stroke order
On reading compounds
- 教諭 【キョウユ】 (licensed) teacher
- 比喩 【ヒユ】 simile, metaphor, allegory, parable
Kun reading compounds
- 例える 【たとえる】 to compare (something) to, to liken, to speak figuratively, to use a simile, to use a metaphor
Readings
- Korean:
- yu
Spanish
- ejemplo
- persuasión
- ejemplificar
- dar ejemplo
- persuadir
Portuguese
French
| 947 | Classic Nelson (Andrew Nelson) |
| 2064 | Japanese Names (P.G. O’Neill) |
| 2100 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 671 | Kodansha Kanji Dictionary (Jack Halpern) |
| 508 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 3979 | Morohashi |
| 553 | New Japanese English Character Dictionary (Jack Halpern) |
| 839 | New Nelson (John Haig) |
| 308 | Remembering The Kanji, 6th edition (James Heisig) |
| 3d9.15 | The Kanji Dictionary |
| 1-3-9 | SKIP code |
| 6802.1 | Four corner code |
| 6803.7 | Four corner code |
| 1-51-40 | JIS X 0208-1997 kuten code |
| 55a9 | Unicode hex code |