| 497 | A Guide To Reading and Writing Japanese (Florence Sakade) |
| 597 | A Guide To Reading and Writing Japanese 3rd edition (Henshall, Seeley and De Groot) |
| 568 | A Guide To Remembering Japanese Characters (Kenneth G. Henshall) |
| 292 | A New Dictionary of Kanji Usage |
| 129 | Classic Nelson (Andrew Nelson) |
| 281 | Essential Kanji (P.G. O’Neill) |
| 526 | Japanese Kanji Flashcards (Max Hodges and Tomoko Okazaki) |
| 120 | Japanese Names (P.G. O’Neill) |
| 3.16 | Japanese for Busy People |
| 520 | Kanji and Kana (Spahn and Hadamitzky) |
| 529 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 423 | Kanji in Context (Nishiguchi and Kono) |
| 767 | Kodansha Compact Kanji Guide |
| 15 | Kodansha Kanji Dictionary (Jack Halpern) |
| 6 | Kodansha Kanji Learner’s Dictionary (Jack Halpern) |
| 6 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 642 | Les Kanjis dans la tete (Yves Maniette) |
| 10299 | Morohashi |
| 15 | New Japanese English Character Dictionary (Jack Halpern) |
| 1781 | New Nelson (John Haig) |
| 635 | Remembering The Kanji (James Heisig) |
| 685 | Remembering The Kanji, 6th edition (James Heisig) |
| 188 | The Kanji Way to Japanese Language Power (Dale Crowley) |
| 453 | Tuttle Kanji Cards (Alexander Kask) |
Jōyō kanji, taught in grade 4
JLPT level N3
265 of 2500 most used kanji in newspapers
Stroke order
On reading compounds
- 必 【ヒツ】 definiteness, certainty
- 必需 【ヒツジュ】 necessary
Kun reading compounds
- 必ず 【かならず】 always, without exception, necessarily, certainly, without fail, positively, invariably
- 必ずしも 【かならずしも】 (not) always, (not) necessarily, (not) entirely, (not) all
Readings
- Korean:
- pil
Spanish
- sin falta
- necesariamente
- inevitable
- ciertamente
Portuguese
- invariavelmente
- inevitável
- certo
French
- nécessairement
- certain
- inévitable
- invariablement
| 359 | 2001 Kanji |
| 0a5.16 | The Kanji Dictionary |
| 1-1-4 | SKIP code |
| 4-5-4 | SKIP code |
| 3300.0 | Four corner code |
| 1-41-12 | JIS X 0208-1997 kuten code |
| 5fc5 | Unicode hex code |
Jōyō kanji, taught in junior high
JLPT level N1
1432 of 2500 most used kanji in newspapers
Stroke order
On reading compounds
- 衰退 【スイタイ】 decline, degeneration, decay, waning, ebbing
- 衰弱 【スイジャク】 weakness, debility, breakdown, prostration
- 減衰 【ゲンスイ】 attenuation, damping, decay
- 盛衰 【セイスイ】 rise and fall, ups and downs, welfare, vicissitudes
Kun reading compounds
- 衰える 【おとろえる】 to become weak, to decline, to wear, to abate, to decay, to wither, to waste away
Readings
- Korean:
- soe, choe
Spanish
- declinar
- rehusar
- menguar
- debilitarse
Portuguese
- decadência
- decadente
- enfraquecer
French
- déclin
- diminuer
- s'affaiblir
| 1456 | A Guide To Remembering Japanese Characters (Kenneth G. Henshall) |
| 1577 | A New Dictionary of Kanji Usage |
| 312 | Classic Nelson (Andrew Nelson) |
| 1501 | Essential Kanji (P.G. O’Neill) |
| 1725 | Japanese Kanji Flashcards (Max Hodges and Tomoko Okazaki) |
| 1676 | Kanji and Kana (Spahn and Hadamitzky) |
| 1791 | Kanji and Kana, 2nd Edition (Spahn and Hadamitzky) |
| 1805 | Kanji in Context (Nishiguchi and Kono) |
| 1622 | Kodansha Compact Kanji Guide |
| 2604 | Kodansha Kanji Dictionary (Jack Halpern) |
| 1333 | Kodansha Kanji Learner’s Dictionary (Jack Halpern) |
| 1806 | Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern) |
| 1908 | Les Kanjis dans la tete (Yves Maniette) |
| 34127 | Morohashi |
| 2100 | New Japanese English Character Dictionary (Jack Halpern) |
| 5432 | New Nelson (John Haig) |
| 1890 | Remembering The Kanji (James Heisig) |
| 2037 | Remembering The Kanji, 6th edition (James Heisig) |
| 1388 | Tuttle Kanji Cards (Alexander Kask) |
| 465 | 2001 Kanji |
| 2j8.1 | The Kanji Dictionary |
| 2-2-8 | SKIP code |
| 0073.2 | Four corner code |
| 1-31-74 | JIS X 0208-1997 kuten code |
| 8870 | Unicode hex code |