to harbor sinister or treacherous intentions; to be cunning and malicious, making one unapproachable.
他表面上很和善，但实际上腹有鳞甲，让人难以捉摸。
He appears kind on the surface, but in reality, he harbors sinister intentions, making him unfathomable.
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to harbor sinister or treacherous intentions; to be cunning and malicious, making one unapproachable.