危険性|きけんせいkikensei

1. noun(degree of) risk; riskiness; danger
   医者いしゃは彼かれにその薬くすりの危険性きけんせいを警告けいこくした。↗

   The doctor alerted him to the riskiness of the medicine.

• SynonymリスクNeutralLoanword for the risk of suffering a loss; common in medicine, investing and daily life, as in 「リスクを取る」. More at home in speech than 危険性, which leans written.
• SynonymおそれNeutralOften in 「〜の恐れがある」, flagging that something bad may happen — weather, legal writing and the like. It points to the possibility; 危険性 weighs the degree of danger.
• Synonym危険きけんNeutralDanger itself, the most common everyday word. 危険性 instead speaks of the likelihood and degree of danger.
• Related危機ききNeutralA crisis — the critical juncture itself, as in 「経営危機」. 危険性 measures how much harm may result.
• Related危難きなんWrittenWritten word for a life-threatening peril or calamity, now rare, as in 「危難を避ける」. 危険性 measures the likelihood and degree of harm instead.
• Related危殆きたいWrittenWritten and rather old-fashioned: a state of extreme danger on the brink of ruin, as in 「危殆に瀕する」. 危険性 simply gauges how high the danger is.
• Related危なさNeutralNominalized form of the adjective 「危ない」; expresses how dangerous something is, with a colloquial flavor, less formal than 危険性.
• Related危うさNeutralHow precarious and unreliable a situation is, as in 「政権の危うさ」 — stresses instability. 危険性 stresses the chance of coming to harm.
• RelatedおっかなさCasualColloquial: how frightening something feels, tinged with the speaker's fear. 危険性 is an objective assessment of danger.
• Antonym安全性あんぜんせいNeutralThe degree of safety, as in 「安全性を確かめる」; the direct opposite of 危険性, which measures the degree of danger.

Use 「危険性」 for how dangerous something potentially is, as in 「事故の危険性」. For risk in daily, medical or financial talk pick 「リスク」; in written prose saying something bad may happen, 「〜の恐れ」 fits. 危険 names danger itself, 危機 a critical moment.

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

1. 危険きけんの虞おそれ。