hazardous

Compared meaning: dangerous, likely to cause harm (adjective).

比较义项：危险的，可能造成伤害或损失（形容词）。

• dangerous

  The default, all-purpose word for anything capable of causing harm; neutral in tone and used for people, places, animals, or actions alike.

  最基本、通用的词，指任何可能造成伤害的事物；语气中性，人、地点、动物、行为都可以用。

  Crossing that busy road without looking is very dangerous.

  不看路就穿过那条繁忙的马路非常危险。

• hazardous 本词

  More formal and technical than 'dangerous'; typically describes conditions, materials, or occupations that pose a specific physical risk, as in official warnings.

  比dangerous更正式、更专业，通常用来描述带有特定人身风险的条件、材料或职业，常出现在官方警示中。

  Handling chemical waste without gloves is extremely hazardous.

  不戴手套处理化学废料是极其危险的。

• risky

  Focuses on the chance of failure or loss rather than physical harm; often used about decisions, plans, or investments where the outcome is uncertain.

  侧重于失败或损失的可能性，而非人身伤害；常用于结果不确定的决定、计划或投资。

  Investing all your savings in one stock is quite risky.

  把所有积蓄都投入一支股票是相当冒险的。

• suicidal

  Much stronger and more dramatic than the others; describes behavior so extreme it seems almost self-destructive, often used with exaggeration for effect.

  语气比其他词强烈得多，形容行为极端到近乎自毁，常带夸张色彩。

  Driving that fast on ice is a suicidal thing to do.

  在冰面上开那么快简直是玩命。

These four words describe something dangerous, but differ in tone. Dangerous is neutral. Hazardous is formal, for risky conditions or materials. Risky means a chance of failure or loss, in decisions. Suicidal is strongest, describing extreme, self-destructive behavior. Not compared: suicidal meaning wanting to die.

这几个词都能形容危险的事物或行为，但程度和使用场合不同：dangerous最常用、语气中性；hazardous更正式、专业，多用于官方警示中描述条件或材料的风险；risky侧重失败或损失的可能性，常用于决定和投资；suicidal语气最强，形容行为极端到近乎自毁，常带夸张色彩。这里不比较suicidal“有自杀倾向的”这一义项。