41 synonyms for rampant such as rearing, epidemic, fanatical, exuberant, erect, and perpendicular. Rampant is an adjective, and its antonyms are controlled and under control.
Epidemic, out of control, out of hand, pandemic, pervasive, rife, spreading like wildfire, unbridled, unchecked, uncontrolled, unrestrained, and widespread.
Fanatical, forceful, intense, passionate, raging, strong, vehement, violent, and wild.
Exuberant, jungly, lavish, lush, luxuriant, productive, profuse, rank, rich, riotous, and vigorous.
Erect, on end, perpendicular, rearing, standing (up), upended, upright, and vertical.