A tell-tale sign that reveals one's true, often cunning or malicious, nature or hidden intentions; evidence of wrongdoing that cannot be concealed.
他表面上装得很友好，但几次不经意的举动，还是露出了狐狸尾巴。
He pretended to be friendly, but a few unintentional actions gave away his true nature.
Era:
Ancient
Frequency:
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