ram·pant 
(rămpənt)
(rămpənt)adj.
1. Extending unchecked; unrestrained: a rampant growth of weeds in the neglected yard.
2. Occurring without restraint and frequently, widely, or menacingly; rife: a rampant epidemic; rampant corruption in city government.
3.
a. Rearing on the hind legs.
b. Heraldry Rearing on the left hind leg with the forelegs elevated, the right above the left, and usually with the head in profile.
4. Architecture Springing from a support or an abutment that is higher at one side than at the other: a rampant arch.
adv.
In an unrestrained and often menacing manner: vandals running rampant in the city.
[Middle English rampaunt, from Old French rampant, present participle of ramper, to ramp; see RAMP2.]
rampan·cy n.
rampant·ly adv.
rampant