An example of rampant is when ants have invaded your kitchen.
A rampant epidemic; rampant corruption in city government.
A rampant growth of weeds in the neglected yard.
A rampant arch.
Origin of rampant
- Middle English rampaunt from Old French rampant present participle of ramper to ramp ramp2
From American Heritage Dictionary of the English Language, 5th Edition
- Recorded since 1382, "standing on the hind legs" (as in heraldry), later, "fierce, ravenous" (1387); from Old French rampant, the past present participle of ramper (“to creep, climb")