infest

The story

1. Latin · derived fromīnfestō“assail, molest”
2. Old French · derived frominfester“to infest”
3. Middle English · inherited frominfesten
4. English todayinfest

From Middle English infesten, from Old French infester (“to infest”), from Latin īnfestō (“assail, molest”, verb), from īnfestus (“hostile”), of uncertain origin.