pest
n. countablen. an insect or animal that causes trouble, especially by damaging crops or food. It can also describe a person who is very annoying.
n. a destructive insect or animal that attacks crops, food, or livestock. Also used figuratively to describe a person who is persistently annoying or troublesome.
The farmer used a spray to keep the pests away from his corn.
My little brother is being a real pest today because he keeps interrupting my work.
While some insects are beneficial to the garden ecosystem, others are classified as pests because they consume the foliage of ornamental plants and spread viral diseases.
From Hungarian Pest, ultimately from Old Church Slavonic пещь (peštĭ, “furnace, oven”). Compare German Ofen (“Buda”, literally “oven”).
Commonly used in agricultural contexts for animals and in informal social contexts for people.