非|ひhi[1]atamadaka (head-high)

1. nounfault; error; mistake
   彼かれは自分じぶんの非ひを認みとめましたか。↗

   Did he admit that he was wrong?
2. noungoing poorly; being disadvantageous; being unfavorable
3. prefixun-; non-; an-

• Synonym過ちあやまちNeutralAn act of doing wrong (「過ちを犯す」), focusing on the wrong act itself; 「非」 is about being in the wrong or at fault, mostly in 「非を認める」 or as a prefix.
• Synonym不始末ふしまつNeutralCareless handling that causes trouble (「火の不始末」), often for fires or scandals; 「非」 covers wrongdoing in general, not a specific incident.
• Synonym過失かしつNeutralNegligence (「過失致死」), stressing carelessness; common in legal contexts. 「非」 is about being at fault or in the wrong.
• Synonym落ち度おちどNeutralA blamable slip or lapse (「こちらに落ち度はない」); more concrete than 「非」, pointing to a specific mistake.
• Synonym過誤かごWrittenWritten/formal prose for an error, common in medical and legal contexts (「医療過誤」); in everyday apologies use 「非を認める」 or 「過ち」.
• Synonym過怠かたいWrittenWritten/formal prose for negligence; in medieval history also a penalty compensating a fault with money or labor. Rare; say 「過失」 or 「過ち」 instead.
• Synonym誤ごWrittenWritten/formal prose, mostly a prefix marking an error (「誤字」「誤報」), rarely used alone; the prefix 「非」 simply negates (「非公式」).
• Related誤りあやまりNeutralAn error (「計算の誤り」), stressing being incorrect or at odds with the facts; 「非」 stresses being in the wrong and open to blame.
• Related難点なんてんNeutralA drawback or difficult point (「価格が難点だ」), also the crux of a problem; 「非」 is about being in the wrong.
• Related瑕疵かしWrittenWritten/formal prose for a flaw (「契約の瑕疵」), mainly legal, for defects in goods or procedures; 「非」 concerns wrongful conduct.
• RelatedデメリットNeutralLoanword for a disadvantage (「デメリットが多い」), often paired with 「メリット」; 「非」 can also mean disadvantage, but colloquially デメリット is the usual word for downsides.
• RelatedウィークポイントNeutralColloquial loanword for a weak spot, common in sports and business; 「非」 means being at fault, not having a weakness.
• Related欠点けってんNeutralThe most general word for a shortcoming (「欠点を直す」), of people or things; 「非」 is about doing wrong or being in the wrong.
• Antonym是ぜNeutralMeans 'here' or 'this moment'; the variant 「是」 also reads 「ここ」 and is not the opposite of 「非」. The 「是」 contrasted with 「非」 as right vs. wrong is 「是（ぜ）」.

Use 「非」 for being in the wrong (「非を認める」) or as a prefix (「非常識」「非公式」). For a wrong act say 「過ち」, for negligence 「過失」, for shortcomings 「欠点」. 「誤り」 is factual error, 「デメリット」 a disadvantage; 「過誤」「瑕疵」 are formal/legal terms.

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

1. 道理どうりに合あわないこと。不正ふせい。
2. 不利ふりであること。うまくゆかないこと。
3. あやまり。欠点けってん。
4. 漢語かんごの名詞めいし・形容けいよう動詞どうしに付ついて、それに当あたらない、それ以外いがいである、などの意味いみを表あらわす。