smell fishy

To be suspect. This term, which refers to the fact that fresh fish do not smell but stale or rotten ones do, has been around since the early nineteenth century. The metaphor turns up in James Payn’s Confidential Agent (1880): “His French is very fishy.”

是可疑的。这个词从19世纪早期就出现了，它的依据是新鲜的鱼是没有味道，而不新鲜或腐烂的鱼则有味道。詹姆斯•佩恩的《机密特工》(1880年)中出现了这样的比喻:“他的法语很可疑。”

smell fishy的意思是在某一件事情上你感到不太对头，不太对劲，某事很可疑，很值得怀疑，似乎有人在进行欺骗。

It appeared to be a real bargain, but I smelled something fishy because the man was in such a hurry to sell it. I was right - later on I found out the car was stolen.

这个价钱是真便宜，可是这人那么急急忙忙要卖掉让我感到不太对头。我还真是没错，后来我发现那辆车是偷来的。