- a person or thing that annoys, esp by imposing itself when it is not wanted; nuisance
- any organism that damages crops, injures or irritates livestock or man, or reduces the fertility of land
- (as modifier): pest control
- rare an epidemic disease or pestilence
WordReference Random House Learner's Dictionary of American English © 2014
- an annoying or troublesome person, animal, or thing;
nuisance:The youngster was a pest on the airplane.
- an insect or other small animal that harms or destroys garden plants, trees, etc.