infest

Etymology

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

verb

1. (transitive) To inhabit a place in unpleasantly large numbers; to plague, harass.
   Insects are infesting my basement!
   I come now to speak of the Pyrates infesting the West-Indies, where they are more numerous than in any other Parts of the World, on several Reasons […] 1724, Daniel Defoe (attributed), “Introduction”, in A General History of the Pirates, 2nd edition, London: T. Warner, page 24
2. (pathology, of a parasite) To invade a host plant or animal.

adj

1. (obsolete) Mischievous; hurtful; harassing.

noun

1. (obsolete) Hostility.
   1590, Edmund Spenser, The Faerie Queene, Book II, Canto Eleven, Stanza 32, Hackett, 2006, p. 191, Like as a fire, the which in hollow cave Hath long bene underkept, and down supprest, With murmurous disdayne doth inly rave, And grudge, in so streight prison to be prest, At last breakes forth with furious infest, And strives to mount unto his native seat […]