百口莫辩 One hundred mouths cannot justify
Explanation
百口莫辩的意思是，即使有许多人为你说话，也无法辩解清楚。它比喻无论怎样辩解也说不清楚，用来形容理亏或无法反驳的尴尬境地。
The idiom "百口莫辩" means that even if many people speak for you, it is impossible to justify yourself. It describes a situation where no matter how you argue, you cannot justify yourself, and is used to describe the embarrassment of being wrong or having no way to refute.
Origin Story
古代有一个故事，说的是一个名叫张三的人，他被冤枉偷了东西，但他百口莫辩，即使有千言万语也无法证明自己的清白。他被关进了监狱，受尽了折磨。最终，真相大白，张三洗清了罪名，但这段经历却让他终身难忘。
There is an old story about a man named Zhang San who was falsely accused of stealing something. He could not defend himself, even if he had a thousand words to say. He was imprisoned and tortured. Finally, the truth came to light, Zhang San was cleared of the crime, but the experience haunted him for the rest of his life.
Usage
百口莫辩常用于形容一个人面对指控时，无法辩解，只能认罪或沉默。
The idiom "百口莫辩" is often used to describe a person who is unable to defend themselves when confronted with accusations and has to plead guilty or remain silent.
Examples
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他被冤枉了，百口莫辩，只能眼睁睁地看着别人误解他。
tā bèi yuān wǎng le, bǎi kǒu mò biàn, zhǐ néng yǎn zhēng zhēng dì kànzhe biérén wù jiě tā.
He was wronged and could not defend himself.
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面对证据确凿的指控，他百口莫辩，只得低头认罪。
miàn duì zhèng jù què záo de zhǐ kòng, tā bǎi kǒu mò biàn, zhǐ děi dī tóu rèn zuì.
Faced with irrefutable accusations, he could not defend himself and had to plead guilty.
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面对众人的质问，他百口莫辩，只能沉默不语。
miàn duì zhòng rén de zhì wèn, tā bǎi kǒu mò biàn, zhǐ néng chén mò bù yǔ.
Confronted with everyone's questioning, he could not defend himself and could only remain silent.
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他百口莫辩，但内心却无比的坦荡。
tā bǎi kǒu mò biàn, dàn nèi xīn què wú bǐ de tǎn dàng.
He could not defend himself, but his heart was filled with righteousness.
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真相大白之后，他才终于百口莫辩，证明了自己的清白。
zhēn xiàng dà bái zhī hòu, tā cái zhōng yú bǎi kǒu mò biàn, zhèng míng le zì jǐ de qīng bái
After the truth came to light, he finally proved his innocence.