Rampancy is a term that is typically used to describe something that is growing or spreading quickly and uncontrollably. However, there are several synonyms that can be used to convey a similar meaning. Some possible options include "proliferation," "propagation," "expansion," "unfettered growth," "escalation," "uncontrolled spread," "rampant proliferation," and "unchecked expansion." Each of these terms can be used in different contexts to convey different nuances, so it is important to choose the right synonym for the situation at hand. Whether you are describing the growth of a disease, the spread of an idea, or the escalation of a conflict, there is likely a synonym for rampancy that will fit the bill.