摘要：褒义：表“大胆无畏的、无所畏惧、浑身是胆、勇往直前、果敢自信的”，强调在困难或风险场景中展现出的勇气与决断力；

“(as) bold as brass”包含两种核心含义，需结合语境区分：

1. 褒义：表“大胆无畏的、无所畏惧、浑身是胆、勇往直前、果敢自信的”，强调在困难或风险场景中展现出的勇气与决断力；

2. 贬义：表“厚颜无耻的、嚣张跋扈、胆大妄为、狂妄放肆、恣意妄为、不知羞耻的”，指不顾他人眼光、毫无顾忌地做出失礼或越界行为。

该短语起源于19世纪英国口语，“brass”（黄铜）在此处并非指金属本身，而是借喻“坚硬、耐磨、不易变形”的特性——黄铜质地坚硬且不易锈蚀，象征人“性格强硬、不受外界影响”的特质。19世纪末又逐渐衍生出“厚颜无耻”的贬义用法。需注意：“as bold as brass”可褒可贬，“as bold as a lion”仅表褒义。如：

He walked up to her at the party, as bold as brass, and asked her to dance.

他在派对上径直走向她，大胆又自信，邀请她跳舞。

She was as bold as brass when she applied for the top job—she had less experience but believed in her ability."

她虽经验不足，但仍果敢地申请了高管职位——因为她相信自己的能力。

She was as bold as brass when she told him she loved him—she didn’t even hesitate.

她毫无犹豫地告诉他“我爱你”，态度果敢又直接。

He turned up at her house as bold as brass, even though she’d refused to see him twice before.

尽管她已经两次拒绝见他，他还是厚颜无耻地出现在她家门前。

As bold as brass, he asked her parents for their blessing on their engagement—they’d only been dating for a month.

他才和她约会一个月，就大胆地向她父母请求订婚许可。

The student was as bold as brass when she challenged the professor’s theory in front of the whole class.

那个学生在全班面前质疑教授的理论，态度果敢又自信。

As bold as brass, he asked the principal if he could skip the exam to attend a competition.

他厚颜无耻地问校长，能否为了参加比赛而不参加考试。

The CEO was as bold as brass when she announced the company would invest all its profits in new technology.

CEO 果敢地宣布公司将把所有利润投入新技术研发，态度坚定。

The competitor was as bold as brass when it copied our product design and sold it at a lower price.

竞争对手厚颜无耻地抄袭我们的产品设计，还以低价售卖。

The diplomat was as bold as brass when she proposed a new peace plan to the conflicting parties.

那位外交官果敢地向冲突双方提出新的和平计划。

The soldier was as bold as brass when he volunteered to sneak behind enemy lines to gather intelligence.

那位士兵主动请缨潜入敌后搜集情报，表现得大胆无畏。

He was as bold as brass to propose to me—especially after I’d made it clear I disliked him! 《傲慢与偏见》

他居然厚颜无耻地向我求婚——尤其是在我明确表示讨厌他之后！

Edith was as bold as brass to speak up for the servants’ rights in front of Father! 《唐顿庄园》

伊迪丝居然在父亲面前为仆人的权利发声，真是大胆果敢！

he criminal was as bold as brass to leave his fingerprint on the murder weapon—he wanted us to find him. 《神探夏洛克》

凶手厚颜无耻（嚣张）地在凶器上留下指纹——他就是想让我们找到他。

来源：翅膀英语一点号