H . G . Wells " invisible man " was invisible and untraceable.
威尔斯 的 “ 隐身人 ” 来无影去无踪,难以寻觅.
辞典例句
It would have phony license plates and the car itself would be untraceable.
车上的执照牌是假的,凭这辆车要追查车主人也是不可能的.
教父部分
He is calling on that line because he knows it's untraceable.
他打那个电话因为他知道无法被追踪.
互联网
"an untraceable source"