pɛst ˈpɛstələn(t)s pleɪɡ a pernicious and malign influence that is hard to get rid of racism is a pestilence at the heart of the nation according to him, I was the canker in their midst any epidemic disease with a high death rate a serious (sometimes fatal) infection of rodents caused by Yersinia pestis and accidentally transmitted to humans by the bite of a flea that has bitten an infected animal