冷淡|れいたんreitan[3]nakadaka (mid-high)

1. na-adjective, nouncool; indifferent; apathetic; half-hearted
   私の演説えんぜつは冷淡れいたんな沈黙ちんもくで迎むかえられた。↗

   My speech was greeted with cold silence.
2. na-adjective, nouncold; cold-hearted; heartless; unkind

• Synonym冷たいつめたいNeutralCovers physical coldness and cold attitudes, as in 「冷たい水」「冷たい態度」; the everyday spoken word, while 「冷淡」 is more written and stresses indifference.
• SynonymそっけないNeutralColloquial; a cold, curt attitude, as in 「素っ気ない返事」; leans toward unkindness.
• Synonym邪険じゃけんNeutralColloquial; harsh and mean-spirited, as in 「邪険に扱う」; stresses rough, unkind treatment.
• Synonym不親切ふしんせつNeutralUnkind or unhelpful, as in 「不親切な説明」; often about service or the help people give.
• SynonymつれないNeutralColloquial; cold and unresponsive, as in 「つれない返事」; said of lovers and friends alike.
• RelatedドライNeutralLoanword for a brisk, unemotional, matter-of-fact stance, as in 「ドライな性格」; not necessarily negative.
• Related冷ややかひややかNeutralLeans written/formal; an icy look or manner, as in 「冷ややかな目」; typically of glances and attitudes.
• Related無情むじょうWrittenWritten/formal; heartless, as in 「無情の雨」; stresses showing no mercy or regard for feelings.
• Related冷酷れいこくWrittenWritten/formal; cruel and ruthless, as in 「冷酷な人」; stronger than 「冷淡」.
• Related無愛想ぶあいそうNeutralCold and unwelcoming, as in 「無愛想な店員」; about not smiling or being pleasant with people.
• Related他人行儀たにんぎょうぎNeutralUndue formality with someone close, as in 「他人行儀な挨拶」; distance between people who are actually friends.
• RelatedよそよそしいNeutralColloquial; distant and reserved, as in 「よそよそしい態度」; often implies a relationship has cooled.
• RelatedけんもほろろNeutralColloquial; flatly and brusquely refusing a request, as in 「けんもほろろに断られる」.
• Related薄情はくじょうNeutralWritten/formal; lacking love or loyalty, as in 「薄情な人」; typically of coldness toward lovers, family or close friends.
• Related冷血れいけつWrittenWritten/formal; cold-blooded and lacking all human feeling, as in 「冷血な人」; a much harsher word than 「冷淡」.
• Related非人情ひにんじょうWrittenWritten/formal; devoid of human warmth or sympathy; found mostly in literary writing.
• Antonym熱心ねっしんNeutralAntonym: enthusiastic and devoted to something, the opposite of 「冷淡」 as indifference.
• Antonym親切しんせつNeutralAntonym: kind and considerate, the opposite of 「冷淡」 as coldness or unkindness.

Use 「冷淡」 for indifference or a cold attitude toward people or things, as in 「冷淡な態度」「政治に冷淡」. In everyday speech 「冷たい」 is the usual choice; for a curt, brusque manner say 「素っ気ない」, and for outright cruelty 「冷酷」 or 「冷血」, both far stronger than 「冷淡」. 「他人行儀」 and 「よそよそしい」 describe distance between people who should be close. The opposites are 「親切」 and 「熱心」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 物事ものごとに熱心ねっしんでないこと。関心かんしんや興味きょうみを示しめさないこと。
2. 思おもいやりがないこと。同情どうじょうや親切心しんせつしんを示しめさないこと。