• synonyms


See more synonyms for infest on Thesaurus.com
verb (used with object)
  1. to live in or overrun to an unwanted degree or in a troublesome manner, especially as predatory animals or vermin do: Sharks infested the coastline.
  2. to be numerous in, as anything undesirable or troublesome: the cares that infest the day.
  3. Archaic. to harass.
Show More

Origin of infest

1375–1425; late Middle English < Latin infestāre to assail, molest, derivative of infestus hostile
Related formsin·fest·er, nounre·in·fest, verb (used with object)un·in·fest·ed, adjective
Can be confusedinfect infest invest
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for infested

ravaged, beset, full, jammed, overwhelmed, crowded, grubby, lousy, ratty, wormy

Examples from the Web for infested

Contemporary Examples of infested

Historical Examples of infested

British Dictionary definitions for infested


verb (tr)
  1. to inhabit or overrun in dangerously or unpleasantly large numbers
  2. (of parasites such as lice) to invade and live on or in (a host)
Show More
Derived Formsinfestation, nouninfester, noun

Word Origin for infest

C15: from Latin infestāre to molest, from infestus hostile
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for infested



late 15c., "to attack, assail, hurt, distress, annoy," from Middle French infester, from Latin infestare "to attack, disturb, trouble," from infestus "hostile, dangerous," originally "inexorable, not able to be handled," from in- "not, opposite of" (see in- (1)) + -festus "(able to be) seized." Sense of "swarm over in large numbers" first recorded c.1600. Related: Infested; infesting.

Show More
Online Etymology Dictionary, © 2010 Douglas Harper

infested in Medicine


  1. To live as a parasite in or on tissues or organs or on the skin and its appendages.
  2. To inhabit or overrun in numbers large enough to be harmful, threatening, or obnoxious.
Show More
Related formsin′fes•tation n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.