pes·ti·lence \ˈpestələn(t)s\noun (-s) Etymology: Middle English, from Middle French, from Latin pestilentia, from pestilent-, pestilens + -ia -y 1.: a contagious or infectious epidemic disease that is virulent and devastating; specifically: bubonic plague 2.: something that is destructive or pernicious < I'll pour this pestilence into his ear — Shakespeare >