PEST

Definition

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. — synonyms: plague, pestilence, pestis
2. noun any epidemic disease with a high death rate. — synonyms: plague, pestilence
3. noun a persistently annoying person. — synonyms: blighter, cuss, pesterer, gadfly
4. noun any unwanted and destructive insect or other animal that attacks food or crops or livestock etc..