Definition

1. Verb (transitive):
   • To live on or in a host organism, typically in large numbers, as a parasite or pest.
   • To overrun or inhabit a place in an annoyingly large or troublesome number.
   • To spread or swarm into a place, causing harm, nuisance, or damage.

Usage and Examples

• As a verb meaning to inhabit as a parasite:
  • Ticks often infest deer and other mammals.
  • The abandoned building was infested with rats.
• As a verb meaning to overrun or swarm:
  • Locusts infested the farmland, destroying the crops.
  • We had to call an exterminator because cockroaches infested the kitchen.
• As a verb meaning to be persistently present in a troublesome way:
  • Spam messages infest my email inbox daily.
  • Corruption infests every level of that organization.

Advanced Usage

• "to be infested with": This is the most common construction, describing a place or host that is overrun.
  • The old mattress was infested with bed bugs.
• "infesting" (present participle/adjective form): Used to describe the ongoing action or state.
  • The infesting insects made the house uninhabitable.

Variants and Related Words

• Infestation (noun): The state of being infested; a large number of pests present in a place.
  • The infestation of termites required extensive treatment.
• Infester (noun): One who or that which infests (less common).
  • The mosquito is a notorious infester of tropical regions.

Synonyms

• Overrun: To spread over and occupy in great numbers.
• Swarm: To move in or form a large, dense group.
• Plague: To cause continual trouble or distress; to pester or harass.
• Invade: To enter in large numbers, especially intrusively.
• Permeate: To spread throughout (often used for non-living things like ideas or smells, but can be analogous).

Phrasal Verbs / Common Constructions

• Infest with: The standard prepositional phrase used with this verb.
  • The garden was infested with aphids.

Related Idioms

• "Riddled with": While not a direct synonym, this idiom is used similarly to describe something full of an undesirable element.
  • His argument was riddled with logical fallacies. (Compare to: His argument was infested with errors.)
• "Crawling with": An informal idiom meaning teeming or full of (usually living things).
  • The picnic area was crawling with ants.

Verb

1. live on or in a host, as of parasites
2. occupy in large numbers or live on a host
   • the Kudzu plant infests much of the South and is spreading to the North
3. invade in great numbers
   • the roaches infested our kitchen