pest Meaning, Definition & Usage

  1. noun a serious (sometimes fatal) infection of rodents caused by Yersinia pestis and accidentally transmitted to humans by the bite of a flea that has bitten an infected animal
    pestilence; plague; pestis.
  2. noun any epidemic disease with a high death rate
    pestilence; plague.
  3. noun a persistently annoying person
    pesterer; cuss; gadfly; blighter.
  4. noun any unwanted and destructive insect or other animal that attacks food or crops or livestock etc.
    • he sprayed the garden to get rid of pests
    • many pests have developed resistance to the common pesticides

WordNet

Pest noun
Etymology
L. pestis: cf. F. peste.
Definitions
  1. A fatal epidemic disease; a pestilence; specif., the plague.
    England's sufferings by that scourge, the pest. Cowper.
  2. Anything which resembles a pest; one who, or that which, is troublesome, noxious, mischievous, or destructive; a nuisance. "A pest and public enemy." South.

Webster 1913