What’s a good freeware dictionary program?

I thought having an offline English dictionary + thesaurus (or as a program) would be more convenient for me than the online options. Is there any good program that doesn’t have any spyware or adware that I can download? Most of them tend to cost money, but I was looking for ones that didn’t.

Everest Dictionary is a free dictionary. There are 37 dictionary databases available at this moment. Everest Dictionary was downloaded more than 2.000.000 times and the number of downloads grows every day.