The term "wild cat" generally refers to any member of the Felidae family that lives in the wild. This includes all the large cats like lions, tigers, leopards, jaguars, and cheetahs, as well as smaller wild cats like bobcats, lynx, and servals.
Domestic cats, even the largest breeds like Maine Coons, are smaller than most wild cats. While they may be larger than some of the smaller wild cats, they are still dwarfed by the big cats.