Meaning
The kanji 鈍 (don) conveys meanings like "dull," "slow," "blunt," "foolish," "obtuse," and "languid." It often describes a lack of sharpness, whether literally for an object or metaphorically for a person's intelligence, senses, or reaction speed. Think of it as a knife that no longer cuts well, or a person who is slow-witted or insensitive.
This character developed as a phono-semantic compound. The left part, 金 (kin/kane), acts as the radical and means "metal." This component hints that the kanji might relate to metallic objects that can be sharpened or dulled. The right part, 屯 (ton/tun), provides the phonetic element. While 屯 generally means "to collect" or "to station," it also historically implied obscurity or sluggishness, which supports 鈍's overall meaning. Together, these parts suggest a metallic object that has lost its keen edge or vigor, becoming ineffective or sluggish.
Therefore, the shape of 鈍 visually links to its meaning by combining the idea of metal with a component suggesting dullness or a lack of swiftness. It brings to mind a once-sharp blade that's become unusable through neglect or age, or a mind that struggles to grasp new ideas. The kanji 鈍 has 12 strokes and is part of the Jōyō Kanji list, meaning it's approved for general use. Japanese junior high school students typically learn it, as do those studying for the JLPT N2 exam.
Readings
On'yomi (音読み) — Chinese-derived readings
The main On'yomi (Chinese-derived reading) for 鈍 is ドン (DON). This reading often appears in compound words, where it consistently expresses dullness, slowness, or obtuseness. These compounds typically have a more formal or academic tone.
鈍感 (donkan) — This term signifies dullness, insensitivity, or thick-headedness, describing a lack of emotional or sensory perceptiveness. Example: 彼は鈍感なので、冗談が通じない。 (He is insensitive, so jokes don't get through to him.)
鈍行 (donkō) — This refers to a local train that stops at every station, literally a "slow train." It emphasizes the leisurely pace of travel. Example: 鈍行に乗って、ゆっくりと景色を楽しんだ。 (I took the local train and slowly enjoyed the scenery.)
鈍重 (donjū) — This compound describes someone or something as clumsy, slow-witted, or ponderous. It suggests heavy, slow movement or a lack of mental quickness. Example: その機械は鈍重だが、とても頑丈だ。 (That machine is ponderous but very sturdy.)
Kun'yomi (訓読み) — Native Japanese readings
The Kun'yomi (native Japanese readings) for 鈍 include にぶ.い (nibu.i), なま.る (nama.ru), なまくら (namakura), and sometimes おそ.い (oso.i). These readings are typically used when the kanji functions as an adjective or is part of a native Japanese verb, often conveying a more direct and expressive nuance.
鈍い (nibui) — This is a common adjective meaning "dull" (for a blade), "slow" (witted), "blunt," or "sluggish." It can apply to many things, from physical objects to mental processes. Example: このナイフは鈍いので、なかなか切れない。 (This knife is dull, so it doesn't cut well.)
鈍る (namaru) — This verb means "to become dull," "to weaken," or "to become sluggish." It implies a decline in sharpness or ability. Example: 練習しないと、感覚が鈍ってしまう。 (If you don't practice, your senses will become dull.)
鈍くら (namakura) — This term refers to a "dull blade." It can also metaphorically describe a "coward" or an "unenthusiastic person." It carries a negative sense of being ineffective or lacking vigor. Example: 彼は鈍くらな性格だ。 (He has a sluggish personality.)
鈍い (osoi) — While おそい usually means "slow" and is commonly written with 遅, 鈍い can also be read as おそい in specific situations. This applies particularly when implying slowness in reaction or progress that feels like dullness. Example: 反応が鈍い。 (The reaction is slow.) (Note: にぶい is generally more common for this specific nuance.)
Common Words & Compounds
The kanji 鈍 frequently appears in various compounds, extending its core meanings of dullness, slowness, and bluntness to different contexts. These range from physical objects to abstract concepts like mental acuity or sensory perception. Understanding these compounds provides a deeper insight into how the kanji is used.
Related to Physical Attributes and Objects:
鈍器 (donki) — This term refers to a blunt weapon, such as a club or a hammer, used for striking rather than cutting. The "dull" aspect here signifies the lack of a sharp edge, making it an impact weapon.
鈍角 (donkaku) — An obtuse angle in geometry. This is an angle greater than 90 degrees but less than 180 degrees. It implies a "blunt" or wide angle, unlike sharp angles.
鈍色 (nibi-iro) — Describes a dark gray or lead color. This color is considered "dull" or muted, lacking brightness or vibrancy. You'll often find this term in classical Japanese literature and art to describe somber or subdued tones.
鈍刀 (dontō) — A dull sword or knife. It literally means a "dull blade," highlighting the loss of sharpness, which makes it ineffective for cutting and potentially dangerous.
Related to Mental State and Perception:
鈍感 (donkan) — Denotes dullness, insensitivity, or thick-headedness. This describes someone who is slow to understand, react, or feel emotions or external stimuli. Such a person might easily miss social cues.
鈍感力 (donkanryoku) — Literally "the power of insensitivity." This modern term describes the ability to be resilient by not overreacting or being overly sensitive to minor setbacks or criticisms. It's about having a "dull" reaction to negativity for one's own well-being, fostering mental toughness.
鈍麻 (donma) — Refers to dullness, insensitivity, or numbness, especially of the senses or mental faculties. For example, a limb might feel 鈍麻 after prolonged pressure, or one's intellect might become 鈍麻 without enough stimulation.
愚鈍 (gudon) — This compound means stupidity or foolishness, combining 愚 (gu; foolish) with 鈍. It describes a deep lack of intelligence or mental quickness, often suggesting a rather hopeless state of dullness.
遅鈍 (chidon) — This term signifies dullness, slowness, or sluggishness, particularly in a mental or intellectual context. It implies a mind that is slow to process information or react, leading to delayed understanding or action.
Related to Movement, Progress, and Skill:
鈍化 (donka) — The act of slowing down, becoming dull, or blunting. This can apply to abstract concepts like economic growth, the pace of change, or even the sharpening of a skill over time. For instance, a market's growth can 鈍化 if demand weakens.
鈍足 (donsoku) — Means slow speed or slow-footedness, often used to describe someone or something physically slow or with poor running ability.
動作が鈍い (どうさがにぶい) — A common expression meaning to be slow in movement or action. This can refer to a person's physical reaction speed or a machine's performance.
勘が鈍る (かんがにぶる) — To lose one's touch or for one's intuition to dull. This vividly expresses a decline in a skill, perceptive ability, or instinct due to lack of practice, age, or disuse.
Example Sentences
長い間使わなかったせいで、ナイフが鈍くなった。
Nagai aida tsukawanakatta sei de, naifu ga nibuku natta.
Because I didn't use it for a long time, the knife became dull.
彼は鈍感な人なので、周りの気持ちに気づかない事が多い。
Kare wa donkan na hito nano de, mawari no kimochi ni kidzukanai koto ga ōi.
He is an insensitive person, so he often doesn't notice others' feelings.
年齢とともに、反応が鈍くなるのは仕方ない。
Nenrei to tomo ni, hannō ga nibuku naru no wa shikatanai.
It's unavoidable that reactions become slower with age.
鈍行は時間がかかるが、景色をゆっくり楽しめる。
Donkō wa jikan ga kakaru ga, keshiki o yukkuri tanoshimeru.
Local trains take time, but you can slowly enjoy the scenery.
毎朝の運動で、体の動きが鈍くならないようにしている。
Maiasa no undō de, karada no ugoki ga nibuku naranai yō ni shiteiru.
I try to keep my body from becoming sluggish with morning exercise every day.
試験の前は、頭の働きが鈍くならないように休養が必要だ。
Shiken no mae wa, atama no hataraki ga nibuku naranai yō ni kyūyō ga hitsuyō da.
Before an exam, rest is necessary so that your mind doesn't become dull.
彼は鈍器で扉を叩き割ろうとした。
Kare wa donki de tobira o tatakiwarō to shita.
He tried to break open the door with a blunt weapon.
寒さで指先の感覚が鈍麻してしまった。
Samusa de yubisaki no kankaku ga donma shite shimatta.
My fingertips became numb due to the cold.
彼女は鈍色の着物を着ていた。
Kanojo wa nibi-iro no kimono o kiteita.
She was wearing a dark gray kimono.
Memory Tip
To remember the kanji 鈍, imagine a "metal" (金) object that has become "dull" or "blunt" because it was neglected and left in a "heap" or "pile" (屯). Picture a finely crafted metallic tool, perhaps an old chisel or a gardening hoe, forgotten among other items. Over time, without proper care or storage, its edge inevitably becomes 鈍 (dull). The 金 radical on the left side of 鈍 clearly signifies "metal," providing a direct meaning link. Meanwhile, the right component, 屯, while meaning "to collect" or "to station," also subtly hints at sounds associated with sluggishness or dullness. Thus, you can visualize a metal object, once sharp, now merely piled up and therefore dull, helping you solidify the kanji's meaning.