happening or spreading in an uncontrolled way
rampant - widespread
‘Rampant’ tends to be used in a negative context. It expresses that something bad, such as crime or a disease, is increasingly widespread and out of control. It tends to be characterized by a destructive wildness or by an absence of restraint.
Rampant government spending is not helping the situation. It will likely lead to a recession.
Disease is spreading rampantly in the city, especially in the more congested areas.
There are rampant rumours circulating the office that the CEO will be stepping down in the next day or two.