上っ調子|うわっちょうしuwatchoushi[4]nakadaka (mid-high)

1. na-adjective, nounflippant; frivolous; shallow

• Synonym軽々しいかるがるしいNeutralAn adjective for rash, ill-considered words and deeds, as in 「軽々しく口にする」; 「上っ調子」 instead stresses a flighty, unsteady attitude.
• Synonym軽薄けいはくNeutralDescribes a frivolous, insincere person and is often used to judge character; 「上っ調子」 instead points to flighty, unsteady conduct.
• Synonym軽佻浮薄けいちょうふはくWrittenA four-character idiom with a strong written flavour: frivolous, shallow and unreflecting; heavier than 「上っ調子」, often used to criticize social mores.
• Synonym浮薄ふはくWrittenWritten language for shallow frivolity, and also for coldness of feeling; in everyday speech 「軽薄」 takes its place.
• Synonym軽佻けいちょうWrittenWritten language for frivolous, rash behaviour; mostly seen inside 「軽佻浮薄」 and rarely alone — daily speech prefers 「軽はずみ」.
• Related浅はかあさはかNeutralPoints to insufficient thought and short-sightedness — shallow ideas; 「上っ調子」 instead targets a frivolous, non-serious attitude.
• Related薄っぺらうすっぺらCasualColloquial; literally describes something very thin, figuratively shallow content or people with no depth; 「上っ調子」 stresses frivolous words and behaviour.
• Related軽いかるいNeutralBasically means light in weight; for people it can suggest frivolity, as in 「軽い男」. Its range of senses is far broader than 「上っ調子」.
• Related皮相ひそうWrittenWritten language for judging only surfaces, as in 「皮相な見方」; it evaluates views and opinions, while 「上っ調子」 evaluates conduct and attitude.
• Related不真面目ふまじめNeutralMeans not serious or half-hearted, focusing on a poor attitude; 「上っ調子」 adds a flighty, feather-light nuance on top.
• Related軽躁けいそうWrittenWritten language for thoughtlessness and restless, unsteady behaviour; rare in daily use — for frivolity 「軽薄」 is the usual choice.
• Related外面的がいめんてきNeutralMeans external or on the surface, describing things rather than calling a person frivolous; it overlaps with 「上っ調子」 only in the shallowness sense.
• Related浮いたういたNeutralThe past attributive form of 「浮く」, seen in 「浮いた話」「浮いた噂」 for romantic gossip and flirtation; for a frivolous attitude use 「上っ調子」.
• Antonym落ち着きおちつきNeutralThe opposite of 「上っ調子」: composure and steadiness. A noun, often in 「落ち着きがない」.
• Antonym真面目まじめNeutralThe opposite of 「上っ調子」: serious, honest and earnest; the most common everyday word, often written 「まじめ」 in kana.

For everyday talk, call a frivolous person 「軽薄」 or 「軽い」, and thoughtless words or acts 「軽々しい」 or 「浅はか」. 「上っ調子」 itself stresses a flighty, unsteady attitude; in formal prose 「軽佻浮薄」 is the heavier equivalent. Antonyms: 「真面目」, 「落ち着き」.

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

1. 軽々かるがるしく、ぞんざいな様子ようす。真面目まじめさに欠かけている状態じょうたい。