definition of
pest

[1] #1 pest n. [plague, pestilence, pestis] 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. wn

[2] #2 pest n. [plague, pestilence] any epidemic disease with a high death rate. wn

[3] #3 pest n. [blighter, cuss, pesterer, gadfly] a persistently annoying person. wn

[4] #4 pest n. 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". wn