the fact of seeming to be right or true, but really being wrong or false

The speciousness of his defence can be shown by a closer look at the evidence. 仔细检查证据就能发现他的辩护看似真实实为虚假。

It was easy to detect the speciousness in some of the speaker's arguments. 很容易看出发言人的论据中那些似是而非的部分。