薄っぺら|うすっぺらusuppera[0]heiban (flat)

1. na-adjective, nounvery thin; flimsy; cheap; shallow
   私は彼かれの薄うすっぺらな性格せいかくが嫌いやだ。↗

   I don't like his shallow personality.

• Synonym薄いうすいNeutralThe everyday word for thin, covering thickness, pale colour and weak concentration; also 「内容が薄い」「関心が薄い」. Neutral, lacking the shabby, derogatory feel of 「薄っぺら」.
• Synonym薄手うすでNeutralThin in make — used mostly of paper, cloth and clothing; a neutral description, without the derogatory slant of 「薄っぺら」.
• Synonym軽薄けいはくNeutralFrivolous and shallow, stressing a person's lack of dignity; very close to 「薄っぺら」.
• Synonym浅いあさいNeutralShallow in the literal sense too; figuratively it means superficial, over a broader range than 「薄っぺら」.
• Related軽々しいかるがるしいNeutralRash and imprudent: about careless words and deeds, not the shallow emptiness 「薄っぺら」 describes.
• Related軽いかるいNeutralThe everyday word for light; it can also mean frivolous, and its range is much wider than 「薄っぺら」.
• Related浅はかあさはかWrittenWritten style: shallow and thoughtless, stressing poor forethought; carries a derogatory tone.
• Related上っ調子うわっちょうしCasualColloquial: flippant and unserious, about a flighty attitude — never about things being physically thin.
• Related粗雑そざつNeutralCoarse and sloppy: about careless, unrefined workmanship, not about thinness.
• Related外面的がいめんてきWrittenWritten style: external, surface-level — stresses that something concerns only the outside, with no hint of frivolity or shabbiness.
• Related不真面目ふまじめNeutralNot serious: criticizes a half-hearted, slack attitude rather than shallow content.
• Related皮相ひそうWrittenWritten and rare: seeing only the surface, typically as 「皮相な見方」.
• Related安手やすでCasualColloquial: cheap and low-grade; about an item's low quality level, close to the shabby feel of 「薄っぺら」.
• Related軽佻浮薄けいちょうふはくWrittenA four-character idiom in formal prose: frivolous words and deeds without deep thought, said of individuals or of social climate; more literary than 「薄っぺら」.
• Related浅薄せんぱくWrittenWritten style: shallow knowledge and thought; close to the figurative sense of 「薄っぺら」.
• Related浮薄ふはくWrittenWritten and rare: frivolous and cold-hearted, stressing an unsteady character and weak human bonds.
• Related軽佻けいちょうWrittenWritten and rare: flippant and restless, stressing a lack of composure; never about physical thinness.
• Antonym厚いあついNeutralAntonym: thick; also deep affection or warm ties — the opposite of the shabby thinness of 「薄っぺら」.
• Antonym深いふかいNeutralAntonym: deep and profound — the opposite of the empty shallowness of 「薄っぺら」.

「薄っぺら」 always carries a dismissive tone: things thin in a shabby, cheap-looking way, or people and talk that are shallow and empty, as in 「薄っぺらな人間」. For plain, neutral thinness choose 「薄い」 (everyday) or 「薄手」 (paper, cloth, clothes). For shallow thinking, 「浅はか」 is the standard pick; 「浅薄」 and 「皮相」 serve in formal prose. For frivolous character, 「軽薄」 is closest, with colloquial 「上っ調子」 and literary 「軽佻浮薄」 as options. 「厚い」 and 「深い」 are the antonyms.

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

1. ぺらぺらに薄うすく貧相ひんそうなさま。
2. 軽薄けいはくなさま。浅薄せんぱくなさま。