真性|しんせいshinsei[0]heiban (flat)

1. nouninborn nature
2. no-adjectivegenuine; intrinsic; essential

• Synonym天性てんせいNeutralInborn character or qualities, good or bad (「天性の明るさ」, 「天性の怠け者」). 「真性」 is more written/formal and can also mean genuine or pure.
• Synonym気質きしつNeutralInnate emotional tendencies, common in daily speech (「穏やかな気質」, 「激しい気質」) and also a psychology term. 「真性」 centers on true nature, not temper.
• Synonym性質せいしつNeutralThe broadest word, for characteristic properties of people or things. 「真性」 highlights the true, inborn side.
• Synonym本性ほんしょうNeutralOne's innate character or true face (「本性を現す」); can also mean a sound, sober mind. 「真性」 puts more weight on purity or genuineness.
• Synonym天資てんしWrittenRare written word for innate endowment, leaning toward ability. Near the inborn-nature sense of 「真性」 but without true/false nuance; daily speech prefers 「資質」 or 「天性」.
• Synonym天質てんしつWrittenRare written word stressing inborn talent or ability. 「真性」 can also mean original, genuine quality; for everyday talk about talent use 「素質」.
• Synonym禀性ひんせいWrittenRare written word for inborn temperament. Close to the inborn-nature sense of 「真性」 but with no true/false nuance; 「天性」 works in everyday speech.
• Synonym賦性ふせいWrittenRare written word for innate nature. Close to the inborn-nature sense of 「真性」 but without the true/false emphasis; say 「天性」 in daily use.
• Synonym資性しせいWrittenRare written word for inborn disposition or talent. 「真性」 can also stress genuine quality; 「資質」 is the everyday choice.
• Synonym稟性ひんせいWrittenA variant spelling of 「禀性」: a rare written word for heaven-endowed temperament. Close to the inborn-nature sense of 「真性」; 「天性」 is the everyday word.
• Related生来せいらいWrittenStresses having something from birth; works as an adverb (「生来怠け者だ」) or as 「生来の」 before nouns. 「真性」 is a noun and also means genuine, as opposed to false.
• Related性格せいかくNeutralThe most common everyday word: tendencies of feeling and will, also traits of things, not only innate. 「真性」 is more written and stresses what's original or genuine.
• Related資質ししつNeutralInnate ability, qualities, or fitness for a role (「指導者の資質」); common in speech too. 「真性」 stresses what's original or genuine, not suitability for a job.
• Related持ち前もちまえNeutralUsually as 「持ち前の」 for one's natural traits (「持ち前の明るさ」); can also mean each person's share of a task. 「真性」 has no such share sense.
• Related素質そしつNeutralInborn potential to develop into something (「音楽の素質」). 「真性」 refers to original quality, not promise for the future.
• Related気性きしょうNeutralInborn temper, especially how fiery or mild it is (「気性が荒い」). 「真性」 does not specifically refer to temper.
• Related気立てきだてNeutralFocuses on whether someone's heart or temper is good or bad (「気立てがいい」). 「真性」 speaks of original or genuine quality, not the heart in particular.
• Antonym仮性かせいWrittenMedical term for a condition with a different cause but similar symptoms or nature (「仮性近視」); the opposite of 「真性」 as to whether a condition is truly of its kind.
• Antonym偽性ぎせいWrittenMedical and academic prefix meaning pseudo (「偽性アルドステロン症」); the opposite of 「真性」 in true vs. false nature. Only written 「偽製」 does it mean imitation or forgery.

「真性」 is mostly medical, used for genuine conditions (「真性近視」) and opposed to 「仮性」 and 「偽性」; it can also mean a pure, inborn nature. For innate character say 「天性」 or 「生来」; for everyday personality, 「性格」.

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

1. ありのままの性質せいしつ。天賦てんぷの性質せいしつ。
2. 純真じゅんしんな性質せいしつ。混まじりけのない性質せいしつ。
3. 医学いがくで検査けんさの結果けっか、疑うたがいのない病気びょうき。