適正|てきせいtekisei[0]heiban (flat)

1. na-adjective, nounreasonable; suitable

• Synonym適切てきせつNeutralMeans exactly right for the situation, as in 「適切な対応」, and covers far more ground; 「適正」 leans toward meeting a set standard, as in 「適正価格」.
• Synonym妥当だとうWrittenWritten-style word for a judgment or conclusion that is sound and holds up, as in 「妥当な判断」; 「適正」 is about quantities or prices meeting a standard.
• SynonymふさわしいNeutralSays something befits a person's status or the occasion, as in 「社長に相応しい人」; 「適正」 is about fitting an objective standard or measure.
• Synonym順当じゅんとうNeutralSuggests things unfolding as reason dictates, as in a match 「順当に勝ち進む」; 「適正」 is about meeting a standard or measure.
• SynonymリーズナブルNeutralMostly means good value or affordable; 「適正価格」 stresses a price that is fair—neither high nor low—not necessarily cheap.
• Synonym正しいただしいNeutralMeans correct, in line with reason or fact; 「適正」 is about meeting a standard or right degree, typically for prices, quantities and handling.
• Synonym正当せいとうNeutralMeans justified by reason or law, as in 「正当防衛」; 「適正」 focuses on degree or quantity being appropriate.
• Synonym適宜てきぎWrittenWritten-style word for acting as circumstances require, often adverbially as in 「適宜休憩する」; 「適正」 describes a state of meeting a standard.
• Synonym適当てきとうNeutralCan mean appropriate, but in speech it often suggests doing things sloppily or half-heartedly; use 「適正」 for meeting a standard to avoid misunderstanding.
• Synonym似つかわしいにつかわしいWrittenWritten word for befitting a person or occasion, often in the negative 「似つかわしくない」; never used for reasonable figures or prices.
• SynonymしかるべきWrittenWritten language for what ought to be done, as in 「然るべき措置」 or 「然るべき金額」; carries a stronger sense of 'as is only proper' than 「適正」.
• Synonym至当しとうWrittenLiterary word for something utterly proper, only natural; in everyday speech 「妥当」 or 「当然」 does the job.
• RelatedよろしいFormalA formal way of saying 「よい」, i.e. that something is acceptable or fine; only loosely related to 「適正」's sense of meeting a standard.
• Related似合わしいにあわしいWrittenSays a person or thing matches well in character or standing; in daily use 「相応しい」 or 「似合う」 is normal, and it never covers numerical reasonableness.
• Related良いよいNeutralA blanket word for good or acceptable with enormous range; 「適正」 specifically means meeting a standard and is mostly found in writing and official prose.
• Related相応そうおうNeutralMeans befitting one's status or ability, as in 「年相応」 or 「それ相応の報酬」; 「適正」 centers on meeting an objective standard.
• RelatedいいCasualThe colloquial all-purpose word for good or fine; 「適正」 is a written-style term reserved for meeting a standard or measure.
• Related公正こうせいNeutralMeans impartial and fair, with no favoritism, as in 「公正な取引」; 「適正」 centers on conformity to a standard.
• Related公平こうへいNeutralMeans treating every party even-handedly; 「適正」 centers on meeting a standard, though in evaluations and selection it too can imply fair handling.
• Related手ごろてごろNeutralSays a size or price is just right and not expensive, as in 「手ごろな値段」, with a colloquial flavor; 「適正」 is the more formal choice.
• Related剴切がいせつWrittenHighly literary, for arguments or wording that are extremely apt and to the point; in daily speech 「適切」 is enough.
• Related適したてきしたNeutralMeans suited to a particular use or purpose, as in 「料理に適した器」; 「適正」 says something itself meets a standard or is of the right degree.
• Antonym過剰かじょうNeutralMeans exceeding the proper range, too much, as in 「過剰在庫」; the opposite of 「適正」 on the side of quantity.
• Antonym不適正ふてきせいWrittenThe direct negative of 「適正」: not conforming to rules or standards, as in 「不適正な会計処理」; common in official documents.
• Antonym過小かしょうNeutralMeans too small or too little, as in 「過小評価」; the opposite of 「適正」 where degree falls short.

Use 「適正」 when a price, quantity or degree meets a proper standard, as in 「適正価格」. For a response that fits the situation pick 「適切」, for a sound judgment 「妥当」, for befitting status 「相応しい」, for a good-value price 「リーズナブル」. 「然るべき」 and 「至当」 are literary; 「適当」 can read as sloppy; 「不適正」「過剰」「過小」 are the opposites.

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

1. 適当てきとうで正ただしいこと。
2. 適当てきとうで正ただしい状態じょうたい。