bubonic plague

bubonic plague, one of three clinical forms of plague, an infectious disease caused by the bacterium Yersinia pestis. Bubonic plague is one of three different types of plague, the other two being septicemic plague and pneumonic plague. Bubonic plague is the most commonly occurring type of plague and is characterized by the appearance of buboes—swollen, tender lymph nodes, typically found in the armpits and groin. For information about the transmission, symptoms, treatment, and historical outbreaks of the disease, see plague.