An injurious plant or animal, especially one harmful to humans.(noun)
A deadly epidemic disease; a pestilence.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "pest" in a sentence
"The term pest derives from the Latin pestis for plague and is used to describe plants (weeds), vertebrates, insects, mites, pathogens and other organisms that occur where we do not want them."
"The flea we might now regard as a pest, and the rat upon which the flea rode we would also classify as a pest, but back then, the word pest didn't apply to either."
"Officially known as the brown marmorated stink bug, the pest is native to Asia and was discovered in Pennsylvania in 1998, according to entomologists at Penn State University."