Emily Dickinson Lexicon

PEST, n. [Fr. peste; L. pestis; It. peste, whence appestare, to infect or corrupt, Sp. apestar. These words may be allied to the Heb. Ch. Syr and Eth. באש, to be fetid, Ar. to beat or throw down, or to a verb of that family. The primary sense is probably to strike or beat, hence a stroke. See Class Bs, No. 25, 39, 48.]

1. Plague; pestilence; a fatal epidemic disease. Let fierce Achilles / The god propitiate, and the pest assuage. – Pope.
2. Any thing very noxious, mischievous or destructive. The talebearer, the gambler, the libertine, the drunkard, are pests to society. Of all virtues, justice is the best; / Valor without it is a common pest. – Waller.