existing in a natural state, as animals or plants; not domesticated or cultivated; wild.

having reverted to the wild state, as from domestication

a pack of feral dogs roaming the woods.

of or characteristic of wild animals; ferocious; brutal.

adjective

animal , brutal , ferocious , fierce , raging , savage , tameless , uncultivated , undomesticated , wild , barbarous , bestial , cruel , fell , inhuman , truculent , vicious , wolfish , untamed