Infest

//ɪnˈfɛst// adj, noun, verb

adj, noun, verb ·Uncommon ·Advanced level

Definitions

Noun
  1. 1
    Hostility. obsolete, uncountable

    "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 […]"

Verb
  1. 1
    To inhabit a place in unpleasantly large numbers; to plague, harass. transitive

    "Insects are infesting my basement!"

  2. 2
    invade in great numbers wordnet
  3. 3
    To invade a host plant or animal.
  4. 4
    live on or in a host, as of parasites wordnet
  5. 5
    occupy in large numbers or live on a host wordnet
Adjective
  1. 1
    Mischievous; hurtful; harassing. obsolete

    "[…] The swarme of scaled snakes Did make an yrksome noyce to heare, as she her tresses shakes. About her shoulders some did craule, some trayling downe her brest, Did hisse, and spit out poison greene, and spirt with tongues infest."

Example

More examples

"Invasive pests include European rabbits, which infest two-thirds of Australia, feral cats, pigs, foxes and cane toads."

Etymology

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

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.