Meaning
The kanji 憶 means memory, recollection, and remembrance. In modern Japanese it rarely stands alone, but its compounds surface across everyday speech, literature, academic writing, and JLPT N1 exams.
The structure tells its own story. On the left stands the radical 忄 — a vertical form of 心 (heart) shared by dozens of kanji dealing with emotion and mental states. On the right is 意, meaning "intention" or "mind." 意 itself contains 心 at its base, giving 憶 two hearts in its structure: one as the left radical, one tucked inside 意.
That double-heart form fits the meaning exactly. Memories live deep in the heart and mind, doubly held, doubly felt. From an etymological standpoint, 憶 is a classic phono-semantic compound (形声文字, けいせいもじ): 忄 supplies the semantic link to heart and mind, while 意 historically provided the phonetic cue for the Chinese-derived reading.
With 16 strokes, 憶 is a high school level Joyo kanji (常用漢字, じょうようかんじ), placing it firmly at JLPT N1. It belongs to the heart-radical family alongside 思 (think), 忘 (forget), and 念 (feel deeply) — characters that map the inner landscape of thought and emotion.
Readings
On'yomi (音読み) — Chinese-derived readings
憶 has one on'yomi: オク (oku). Since 憶 almost never appears as a standalone word, this reading surfaces almost exclusively inside compounds (熟語, じゅくご). Four are worth learning in depth:
- 記憶 (kioku) — memory, recollection. The most common word built from 憶, used across casual conversation, medical contexts, and academic writing alike. Natural collocations include 記憶力がいい (good memory) and 記憶に残る (to stick in memory).
- 追憶 (tsuioku) — reminiscence, nostalgic recollection. A literary word for looking back on the past with feeling. Common in memoir titles and poetic contexts.
- 憶測 (okusoku) — speculation, conjecture. Used when conclusions are drawn without solid evidence. A staple of news reporting and formal discourse.
- 回憶 (kaioku) — retrospection. A formal, literary term for reflecting on memories.
Kun'yomi (訓読み) — Native Japanese readings
憶 has no standard kun'yomi in the Joyo kanji table. It functions almost entirely through on'yomi compounds.
Some older dictionaries list おぼ.える (oboeru) as an unofficial kun'yomi meaning "to remember." In modern Japanese, however, that role belongs to 覚 — the word おぼえる is written 覚える, not 憶える. The 憶える spelling turns up in older fiction occasionally, but for the JLPT, the on'yomi compounds are what matter.
Common Words & Compounds
憶 does its real work inside compound words. The key ones, grouped by meaning:
Memory and Recollection:
- 記憶 (kioku) — memory, recollection. The workhorse of this set: daily conversation, academic writing, and medical contexts all rely on it.
- 記憶力 (kiokuryoku) — memory capacity. Describes how strong or weak someone's recall is.
- 記憶喪失 (kioku soushitsu) — amnesia, memory loss. Frequent in fiction and clinical contexts.
- 短期記憶 (tanki kioku) — short-term memory. Standard in psychology and education.
- 長期記憶 (chouki kioku) — long-term memory. The counterpart to 短期記憶.
- 記憶障害 (kioku shougai) — memory impairment or disorder.
- 追憶 (tsuioku) — reminiscence, nostalgic recollection. More literary in tone.
- 回憶 (kaioku) — retrospection. Formal and literary.
Speculation and Inference:
- 憶測 (okusoku) — speculation, conjecture. Essential for reading news articles and formal texts.
- 憶断 (okudan) — arbitrary judgment, unfounded conclusion. More formal and literary.
Example Sentences
彼は子供の頃の記憶がほとんどない。
Kare wa kodomo no koro no kioku ga hotondo nai.
He has almost no memories of his childhood.
記憶力を鍛えるために、毎日単語を練習している。
Kiokuryoku wo kitaeru tame ni, mainichi tango wo renshuu shite iru.
I practice vocabulary every day to train my memory.
それは単なる憶測にすぎません。証拠を見せてください。
Sore wa tannaru okusoku ni sugimasen. Shouko wo misete kudasai.
That is nothing but speculation. Show me the evidence.
祖父は戦争の追憶を静かに語った。
Sofu wa sensou no tsuioku wo shizuka ni katatta.
My grandfather quietly recalled his memories of the war.
記憶喪失になってしまい、自分の名前さえ思い出せなかった。
Kioku soushitsu ni natte shimai, jibun no namae sae omoidasenakatta.
I lost my memory and couldn't even recall my own name.
長期記憶と短期記憶は脳の異なる部分で処理されると言われている。
Chouki kioku to tanki kioku wa nou no kotonaru bubun de shori sareru to iwarete iru.
Long-term and short-term memory are said to be processed in different parts of the brain.
犯人についての憶測がSNS上で飛び交っていた。
Han'nin ni tsuite no okusoku ga SNS-jou de tobikatte ita.
Speculation about the culprit was spreading wildly across social media.
彼女との楽しい記憶は、何年たっても色褪せない。
Kanojo to no tanoshii kioku wa, nannen tatte mo iroasenai.
Happy memories with her never fade, no matter how many years pass.
彼の記憶の中に、あの夏の日はいつまでも残り続けた。
Kare no kioku no naka ni, ano natsu no hi wa itsu made mo nokori tsuzuketa.
That summer day kept living on in his memory, never fading.
Memory Tip
Look at 憶's structure: 忄 (heart) on the left, 意 (mind, intention) on the right — and 意 hides another 心 at its base. Two hearts, one kanji. An ordinary thought needs just one. A memory — something precious, deeply felt — takes both to hold.
That image maps directly onto how memory works. The more emotion behind an experience, the longer it stays. 憶 encodes that fact in its very shape. Next time you see this character, picture two hearts holding a single memory in place.