Learner's definition of RAMPANT
[more rampant; most rampant]
1 usually disapproving — used to describe something that is very common or that is spreading very quickly and in a way that is difficult to control
There is evidence of rampant corruption in the local government.
Rumors of her engagement were rampant. = Rumors of her engagement ran rampant. [=there were many rumors that she was engaged to be married]
2 : growing quickly and in a way that is difficult to control