it means something that you doubt or feel suspicious about.
"You know, I don't trust that company. There is something fishy about their money situation."
Origin:The meaning of this idiom is something “fishy” of doubtful origin but can be related to old fishes (not good to eat) with bad odour caused by a chemical which is released when fish begins to break down.
There's something fishy about a 1970 car with only 5000 km.
The salesman looked nice but when he told us about the 0% financing, the deal seemed a little fishy
Discuss with your group and write your own definition of the idiom, provide three examples for this idiom. Post it in the blog.