質|しつshitsu[0]heiban (flat)

1. noun, noun (suffix)quality; value
   お茶ちゃの質しつは下さがりつつある。↗

   The quality of tea is going down.
2. nounnature; inherent quality; character
3. nounlogical quality

• SynonymクオリティNeutralLoanword for quality, used mostly of products and works, as in 「クオリティが高い」; common in colloquial speech.
• Synonym品質ひんしつNeutralQuality of goods or services, as in 「品質管理」「サービスの品質」; 「質」 also covers people's character and the nature of things.
• Synonym性質せいしつNeutralThe nature or properties of a thing or person, as in 「金属の性質」; describes objective traits, while 「質」 grades how good or bad.
• Synonym特性とくせいNeutralQualities unique to a particular thing, as in 「製品の特性」; stresses what sets it apart.
• Related性格せいかくNeutralA person's temperament, as in 「明るい性格」, or the character of things; 「質」 judges how good or bad something is.
• Related素質そしつNeutralInborn talent that can be developed, as in 「音楽の素質がある」; the focus is on potential.
• Related本質ほんしつNeutralThe fundamental nature of something, as in 「問題の本質」; abstract and leaning to written prose.
• Related気質きしつWrittenAn innate temperament or emotional tendency, as in 「神経質な気質」; a psychological term of written prose; 「質」 grades good or bad.
• Related本性ほんしょうWrittenOne's true inborn nature, as in 「本性を現す」; often negative in shade; a written-style word; 「質」 grades good or bad.
• Related性せいNeutralRead せい, as 'nature' it works mostly as a suffix, as in 「安全性」「可能性」; on its own it usually means sex or gender.
• Related資質ししつNeutralInnate abilities and qualities, as in 「リーダーの資質」; often used to judge whether someone fits a role.
• Related天性てんせいNeutralAn inborn disposition or talent, as in 「天性の明るさ」; stresses what one is born with.
• Related気性きしょうNeutralOne's inborn temper, as in 「気性が激しい」; centers on the strength of emotional reactions.
• Related性分しょうぶんNeutralAn inborn disposition, as in 「じっとしていられない性分」; colloquial, often with a tone of explaining oneself.
• Related真性しんせいWrittenA written-style word for the genuine, original nature; in medicine it marks true conditions; fairly narrow in use.
• Related天資てんしWrittenA written-style word for innate endowments; rarely used in modern Japanese.
• Related天質てんしつWrittenA written-style word for natural talent; rarely used in modern Japanese.
• Related賦性ふせいWrittenA written-style word for innate disposition; virtually unused today.
• Related資性しせいWrittenA written-style word for one's innate nature and talents; rarely used today.
• Related気稟きひんWrittenA written-style word for innate temperament; virtually unused today.
• Antonym量りょうNeutralQuantity or amount; the opposite of 「質」 in the quality-versus-quantity contrast, as in 「質より量」.

Use 「質」 for how good or bad something is — 「質が高い」. For goods and services say 「品質」, or the loanword 「クオリティ」 in casual talk about products and works. For traits of things use 「性質」 or 「特性」. For people: 「性格」 for temperament, 「素質」/「資質」 for inborn potential, 「天性」 for what one is born with, 「気性」 for temper, 「性分」 colloquially. 「本質」 is a matter's essence; 「本性」 one's true, often ugly self. 「性」 works as a suffix like 「安全性」. 「量」 is the opposite in quality-versus-quantity talk. The rest are written-style, several now rare.

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

1. （しつ）ある事物じぶつが備そなえる、他たの事物じぶつとその事物じぶつが近ちかいのか遠とおいのかを表あらわし、その事物じぶつがどんなものなのかを認識にんしきさせるもの。特とくに物ものの場合ばあいは、その数かずではなく、個々ここの物ものに注目ちゅうもくして認識にんしきされるもの。性質せいしつ。
2. （しつ）事物じぶつの良し悪よしあし。特とくに物ものの場合ばあいは、その数かずではなく、個々ここの物ものに注目ちゅうもくして認識にんしきされる良し悪よしあし。品質ひんしつ。
3. （しつ）abc-tripleに対たいしてq(a,b,c)=(log c)/(log (rad(abc)))と定義ていぎされる量りょう。ただし、rad(x)は根基こんき関数かんすうである。