To kill savagely and indiscriminately
He expected these days to be his last, but he'd give the order to decimate the entire state if it meant humanity as a whole survived.
Brutality - Decimate the losing player with a long series of attacks.
Girls during slumber parties have been known to decimate the contents of their hosts' kitchens.
Get behind enemy lines to decimate the threat in life-like fire fights.
These plants help control the ground beetle population which can quickly decimate young cucumbers and prevent the blossoms from forming fruit.