pest

1 a widespread disease resulting in a high rate of death <one of the great pests of the 20th century was the influenza epidemic of 1918, which killed millions across the globe> Synonyms plague, pestilenceRelated Words murrain; epidemic, pandemic; affection, affliction, ailment, contagion, illness, infection, infirmity, malady, sickness; blight, curse, scourge

2 one who is obnoxiously annoying <stop being a pest to your sister and go find something else to do> Synonyms annoyance, annoyer, bother, gadfly, gnawer, nudnik (also nudnick), pain, persecutor, nuisance, tease, teaserRelated Words headache; harrier, heckler, interrupter (also interruptor); hassle, plague; harasser, molester, tormentor (also tormenter), torturerNear Antonyms charmer, smoothy (or smoothie); comforter, solacer, soother

3 something that is a source of irritation <a never-ending construction project that continues to be a pest for motorists> Synonyms aggravation, aggro [British], bother, botheration, bugbear, exasperation, frustration, hair shirt, hassle, headache, inconvenience, irk, irritant, nuisance, peeve, annoyance, rub, ruffle, thorn, trial, vexationRelated Words discomfort, fleabite, pinprick; affront, insult, offense (or offence); upset, worry; affliction, albatross, burden, cross, curse, menace, millstone, plague, sore; anxiety, plight, predicament, tribulation, trouble; hang-up, pet peeve, problem; annoyer, disturber, harasser, mischief, offender; pandora's boxNear Antonyms delight, joy, pleasure