1 unchecked, uninhibited, unrestrained, wild, uncontrolled, out of control, out of hand, frenzied, unbridled, uncontrollable, violent:
He was a victim of rampant jealousy. Jennie could hardly be described as a rampant feminist.
2 profuse, unbounded, abounding, flourishing, rife, widespread, everywhere, epidemic, pandemic, prevalent, unrestrained, unchecked, running wild, uninhibited, indiscriminate, wild, uncontrolled; in control, holding sway, in full sway, dominant, predominant; exuberant, rank, luxuriant:
Before Masterson became sheriff, vice and crime were rampant in the town.