Translation guide
Describes someone who is slow to understand, think, or react. Japanese has several nuanced terms ranging from mild to insulting, often used for being dense, dull, or mentally slow.
To describe someone who takes time to grasp things, not necessarily unintelligent, just a bit slow on the uptake.
Literally 'dull', can refer to physical slowness or mental dullness. Commonly used for being slow-witted or thick-headed.
彼は少し鈍いけど、優しい人だ。
He's a bit slow-witted, but a kind person.
Colloquial, often used for someone who is slow in action or thought, a bit dopey.
あいつはとろいから、説明してもわからないよ。
That guy is so slow-witted, he won't get it even if you explain.
Literally 'slow mental rotation', a common phrase meaning slow on the uptake.
彼は頭の回転が遅いから、冗談が通じない。
He's slow-witted, so jokes don't get through to him.
To describe someone who is stubbornly slow to understand, often missing obvious things.
Insensitive, thick-skinned, or dense. Often used for someone who doesn't pick up on feelings or hints.
彼女は鈍感だから、彼の気持ちに気づかない。
She's so dense she doesn't notice his feelings.
Stupid, foolish, or slow-witted. Can be insulting, implying a lack of common sense.
Poor at picking up on things, slow to catch on. Often used for social situations.
彼は察しが悪くて、空気が読めない。
He's slow on the uptake and can't read the room.
To describe someone with low intelligence or cognitive slowness, often used in a derogatory or medical sense.
Foolish and dull, a strong literary term for stupidity.
彼の愚鈍な行動には呆れる。
I'm appalled by his foolish behavior.
Stupid, dull-witted. Very rare and literary.
魯鈍な者には理解できないだろう。
A dull-witted person wouldn't understand.
Using 遅い (おそい) for a person's wit is unnatural. It means physically slow or late. Use 鈍い or 頭の回転が遅い instead.
鈍い (にぶい) is a general adjective for dullness (mental or physical). 鈍感 (どんかん) specifically means insensitive or thick-skinned, often in social contexts.
Making such a dumb mistake...