“sound as a bell”的词源核心聚焦于“sound”与“bell”的双重隐喻叠加：16世纪时，“sound”已从“（物体）结构坚固、无破损”的本义，衍生出“（人）身体健康、精神状态良好”的抽象义；而“bell”（钟）因制作工艺要求极高——完好的钟能发出清脆、均匀、无杂音的声响，一旦有裂痕则音色浑浊，成为“完好无损”的天然象征。至今成为英语中高频口语表达。其核心语义为 “（人）身体健康、精神饱满；（事物）完好无损、功能正常”，结构具有不可拆分性：“sound”在此处为系动词（而非实义动词“听起来”），表“处于某种状态”；“as a bell”是固定方式状语，喻指“像完好的钟一样”。需特别注意：该短语仅用于正面描述，无负面或中性用法，且口语色彩浓厚，正式书面语中可用于描述事物完好，但描述人体健康时多限于日常对话。如：

After a week of rest, she’s sound as a bell and ready to go back to work.

休息了一周后，她身体好得很，已经准备好回去工作了。

The student was sick last month, but now he’s sound as a bell and topping his.

这个学生上个月生病了，但现在他身体好极了，还在班里名列前茅。

After 50 years of marriage, both of them are still sound as a bell—physically and emotionally.

结婚50年了，他们俩身体和情感状态都依然好得很。

She’s always full of energy and sound as a bell—everyone wants to be friends with her.

她总是活力满满、状态极佳，所有人都想和她做朋友。

The old car has been maintained well, and it’s still sound as a bell after 20 years.

这辆旧车保养得很好，20年后依然完好无损。

The military equipment was tested rigorously, and every piece was sound as a bell.

这批军事装备经过了严格测试，每一件都完好无损。

Even though they broke up last year, he’s still sound as a bell—no hard feelings at all.

尽管他们去年分手了，但他状态好得很——一点芥蒂都没有。

The diplomatic agreement was reviewed thoroughly, and its terms were sound as a bell.

这份外交协议经过了全面审查，其条款完好无缺（无漏洞）。

Don’t worry about Ross—he got over the breakup fast, and now he’s sound as a bell. 《老友记》

别担心罗斯——他很快就从分手中走出来了，现在状态好得很。

The master had a minor accident yesterday, but today he’s sound as a bell—ready for the dinner party.

老爷昨天出了点小意外，但今天身体好得很，已经准备好参加晚宴了。《唐顿庄园》

Our old sofa is 10 years old, but it’s still sound as a bell—we’re not buying a new one.

我们的旧沙发已经10年了，但依然完好无损，就不买新的了。《摩登家庭》