pest meaning and definition

PEST noun

Definition of pest (noun)

1. 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
   • synonyms: pestilence, pestis, plague
2. any epidemic disease with a high death rate
   • synonyms: pestilence, plague
3. a persistently annoying person
   • synonyms: blighter, cuss, gadfly, pesterer
4. 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"