rampant

adjective

• Rearing on both hind legs with the forelegs extended.

  "The Vienna riding school displays splendid rampant movement."

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

  "Weeds are rampant in any neglected garden."

• Rife, or occurring widely, frequently or menacingly.

  "There was rampant corruption in the city."