Translation guide
The state of being mentally weak, lacking intelligence, or unable to make sound judgments. In Japanese, this concept is expressed through various words and phrases that describe intellectual deficiency, foolishness, or mental weakness, often with different nuances and levels of politeness.
Describing someone as generally unintelligent, slow-witted, or lacking mental sharpness.
A common noun meaning foolishness or stupidity. It refers to a lack of intelligence or good judgment. Can be used in both formal and informal contexts.
彼の愚かさには驚かされる。
I am amazed at his foolishness.
Literally 'low ability', this is a more direct and somewhat harsh term for feeble-mindedness or mental deficiency. Often used in medical or derogatory contexts.
彼は低能だと言われている。
He is said to be feeble-minded.
A more clinical phrase meaning 'low intelligence'. It is less emotionally charged than 低能 and can be used in educational or psychological discussions.
知能の低さが学習の妨げになっている。
Low intelligence is hindering his learning.
Means dullness or slowness, often referring to mental slowness. It implies a lack of sharpness or quick-wittedness.
彼の頭の鈍さが問題だ。
His mental dullness is a problem.
Focusing on actions or decisions that show poor judgment, rather than inherent intelligence.
Refers to a foolish act or folly. It emphasizes the action rather than the person's overall intelligence.
彼の愚行は会社に大きな損害を与えた。
His foolish act caused great damage to the company.
Means shallowness or superficiality of thought, leading to poor judgment. It implies a lack of foresight or depth.
彼の浅はかさが原因で計画は失敗した。
His shallowness caused the plan to fail.
A common phrase meaning 'not thinking enough' or 'lacking thought'. It describes a failure to consider things properly.
彼は考えが足りないから、いつも失敗する。
He always fails because he doesn't think things through.
Referring to intellectual disability or cognitive impairment in a clinical sense.
The standard term for intellectual disability. It is the appropriate and respectful term in medical, educational, and legal contexts.
彼は軽度の知的障害がある。
He has a mild intellectual disability.
Describing someone who is easily swayed, lacks firmness of mind, or is gullible.
Means weak-willed or lacking determination. It often implies being easily influenced or unable to stick to decisions.
彼は意志薄弱で、すぐに誘惑に負ける。
He is weak-willed and easily gives in to temptation.
Means 'easily swept along' or 'easily influenced'. It describes a person who goes along with others without strong opinions.
彼女は流されやすい性格だ。
She has a personality that is easily influenced.
The English term 'feeble-mindedness' is outdated and can be offensive. In Japanese, choose words based on context: use 愚かさ for general foolishness, 知的障害 for clinical intellectual disability, and 意志薄弱 for weak-willedness. Avoid using 低能 or 精神薄弱 unless in historical contexts, as they are derogatory.
愚かさ refers to a general lack of intelligence or wisdom, while 浅はかさ specifically points to shallow thinking or lack of foresight. 愚かさ can describe a person's nature, whereas 浅はかさ often describes a particular action or decision.
An older term for mental retardation or feeble-mindedness. Now considered outdated and potentially offensive; replaced by 知的障害 in modern usage.
This term is outdated and may be offensive. Use 知的障害 instead.
精神薄弱という用語は現在では使われない。
The term 'mental deficiency' is no longer used today.