Translation guide
The state or quality of not thinking about the consequences of one's actions or the feelings of others; lack of consideration or care.
Describing someone who acts without thinking about how it affects others, often causing inconvenience or hurt.
A common phrase meaning 'lacking consideration/thoughtfulness.' It directly points out the absence of empathy or care.
彼は思いやりがない。
He is thoughtless.
Saying something like that is really thoughtless.
Literally 'insensitive,' this word describes someone who is tactless or oblivious to others' feelings. Often used for blunt or careless remarks.
彼の無神経な発言に傷ついた。
I was hurt by his thoughtless remark.
無神経な人だね。
What a thoughtless person.
Means 'lacking consideration/attention.' Slightly more formal, often used when someone fails to take necessary care in a situation.
彼の行動は配慮が足りなかった。
His actions were thoughtless.
Means 'not attentive' or 'not quick to notice what needs to be done.' Implies a lack of thoughtfulness in anticipating others' needs.
彼は気が利かないから、手伝ってくれない。
He's thoughtless, so he never helps out.
Describing impulsive or careless behavior that leads to mistakes or problems.
Means 'rash' or 'imprudent.' Used for actions done without careful thought, often leading to negative outcomes.
軽率な行動は避けるべきだ。
You should avoid thoughtless actions.
彼の軽率な判断でプロジェクトが失敗した。
The project failed due to his thoughtless decision.
Literally 'without thought.' A straightforward, slightly colloquial way to say someone acts without thinking.
考えなしに行動すると失敗するよ。
If you act thoughtlessly, you'll fail.
彼は考えなしだ。
He is thoughtless.
Means 'indiscreet' or 'lacking judgment.' Often used for foolish or reckless behavior.
Means 'reckless' or 'foolhardy.' Emphasizes a daring, thoughtless disregard for danger.
Describing a state of not paying attention or forgetting things due to lack of thought.
An adverb/na-adjective meaning 'carelessly' or 'absent-mindedly.' Often used for minor mistakes or forgetfulness.
うっかり約束を忘れてしまった。
I thoughtlessly forgot the appointment.
うっかりミスが多い。
I make a lot of thoughtless mistakes.
Means 'vacantly' or 'absent-mindedly.' Describes a state of not thinking clearly or being spaced out.
Both describe a lack of consideration, but 思いやりがない focuses on the absence of empathy or kindness, while 無神経 emphasizes insensitivity to others' feelings or social cues. 無神経 is often used for blunt or tactless remarks.
彼は思いやりがないから、友達が少ない。
He has few friends because he is thoughtless (lacks empathy).
彼女の無神経な言葉に皆が黙った。
Everyone fell silent at her thoughtless (insensitive) words.
The direct translation '思考の欠如' (shikou no ketsujo) is rarely used in natural Japanese. It sounds overly clinical or philosophical. Use the expressions above depending on the nuance you want to convey.
無分別な発言は控えてください。
Please refrain from thoughtless remarks.
向こう見ずな挑戦だった。
It was a thoughtless challenge.
ぼんやりしていて電車を乗り過ごした。
I was thoughtless and missed my train stop.