Sentence:  Bubonic plague had been in relative abeyance since the 1660s, and its explosion into Marseille and Provence in 1720 confirmed the ability of government, through quarantines and <WSD>cordons sanitaires</WSD>, to hem the disease in and prevent its diffusion across the country. 
Meaning of the word marked with <WSD> tags:  A barrier (physical or administrative) to prevent the spread of disease.