rash

Compared meaning: acting boldly or without much thought about risk (adjective).

比较义项：形容人做事敢于冒险、不顾风险或不假思索地行动（形容词）。

• bold

  Positive in tone: praises confident, courageous action taken despite risk, without suggesting carelessness; typically describes admired decisions, plans, or people.

  bold 是褒义词：赞扬一种尽管有风险仍自信、勇敢采取的行动，并不暗示不计后果；通常用来形容受人赞赏的决定、计划或人物。

  Her bold decision to launch the startup alone impressed even her harshest critics.

  她独自创业的大胆决定，甚至让最严厉的批评者都印象深刻。

• reckless

  Negative and strong: describes acting with complete disregard for danger or consequences, often endangering other people; commonly used for careless driving, spending, or behavior.

  reckless 是贬义且语气较强的词：形容完全不顾危险或后果的行为，常常危及他人；多用于形容鲁莽的驾驶、花钱或行为。

  Speeding through a school zone while texting is reckless and puts children in danger.

  在校区一边发短信一边超速是鲁莽的行为，会把孩子们置于危险之中。

• rash 本词

  Negative but milder: describes acting too quickly on impulse without thinking carefully, especially about the outcome for oneself; does not necessarily endanger other people.

  rash 是贬义词，但语气比 reckless 轻：形容做事过于急躁、缺乏周全考虑，尤其是没顾及对自己造成的后果，不一定危及他人。

  Quitting her stable job on a whim was a rash move she later regretted.

  一时冲动辞去稳定的工作是一个轻率的举动，她后来很后悔。

Bold, reckless, and rash describe risky action, but tone differs. Bold is positive, praising brave, confident action. Reckless and rash are negative: reckless shows complete disregard for danger, harming others; rash means acting too quickly, without thinking. The noun rash (a skin condition) is excluded.

这三个词都能形容“不顾风险地行动”，但语气褒贬不同：bold 是褒义词，强调自信、敢作敢为；reckless 和 rash 都是贬义词，强调不计后果或不假思索。reckless 语气最重，侧重完全无视危险、可能伤及他人；rash 语气较轻，侧重做事太急、缺乏考虑，但不一定牵涉他人安全。这里不比较 rash 作名词表示“皮疹”的意思。