Translation guide
Describes someone who is slow to understand, stubborn, or insensitive. Japanese has different words for intellectual slowness, stubbornness, and insensitivity.
Describing someone who is intellectually slow or dull.
Means 'slow' or 'dull' in a general sense, including mental slowness. Often used in the phrase 頭の回転が鈍い (slow-witted).
Describing someone who is obstinate or refuses to change their mind.
Standard word for stubborn or obstinate. Often used for someone who won't listen to reason.
Describing someone who is oblivious to others' feelings or social cues.
鈍い (にぶい) is a general term for slowness or dullness, including mental slowness. 鈍感 (どんかん) specifically refers to insensitivity or being thick-skinned, often about emotions or social awareness.
He is slow on the uptake.
Colloquial adjective meaning slow, sluggish, or dim-witted. Often used for someone who is slow to react or understand.
あいつはとろいから、説明しても無駄だ。
That guy is so thickheaded, explaining is pointless.
Formal or literary term meaning stupid or dull. Stronger and less common in everyday speech.
彼の愚鈍な態度には呆れる。
I'm amazed at his thickheaded attitude.
父は頑固で、私の意見を聞こうとしない。
My father is thickheaded and won't listen to my opinion.
Similar to 頑固 but emphasizes obstinacy and being set in one's ways.
彼は意固地になって謝らない。
He's being thickheaded and won't apologize.
Literally 'head is hard', meaning inflexible or stubborn in thinking.
あの人は頭が固くて、新しい考えを受け入れない。
That person is thickheaded and won't accept new ideas.
Means insensitive or thick-skinned, often used for someone who doesn't notice others' feelings.
彼は鈍感で、彼女が怒っているのに気づかない。
He's so thickheaded he doesn't notice she's angry.
Literally 'can't read the air', meaning unable to pick up on social cues. Often abbreviated as KY.
彼は空気が読めないから、場違いなことを言う。
He's so thickheaded he says inappropriate things.