Rampant

adjective

1. Rearing on both hind legs with the forelegs extended.

   "The Vienna riding school displays splendid rampant movement."

2. Rearing up, especially on its hind leg(s), with a foreleg raised and in profile.
3. Tilted, said of an arch with one side higher than the other, or a vault whose two abutments are located on an inclined plane.
4. Unrestrained or unchecked, usually in a negative manner.

   "Weeds are rampant in any neglected garden."

5. Rife, or occurring widely, frequently or menacingly.

   "There was rampant corruption in the city."